My husband talks all day and worries about things that aren't happening. How do I keep myself from going crazy?

It is really stressful to have a spouse with dementia, isn't it? And you may reach a point where it really will be better for both of you for him to be in a care facility. You can be his loving wife and visit him, and others can handle the day-to-day care.

But until you are ready for that, try to follow Carerick's example and don't let his gibberish upset you. And BarbBrooklyn is right that drugs can sometimes help. Is he on any? Perhaps a dosage change is in order.

It sounds like he is having delusions that worry him. That is quite common in dementia, but that is little consolation. Reassure him and then redirect him if you possibly can. "I'll take care of that. It will be all right. For now I'm going to have a brownie and some coffee. Will you join me?"

It is best not to argue. If he says "There are bats upstairs!"
not helpful: "We don't have an upstairs!"
better: "OK, I'll call the exterminator to set some traps. Will you help me deadhead the flowers in the front yard?"

It varies from person to person, but often they won't remember or follow up. If he does, and asks "When are the exterminators coming," again be reassuring and try to redirect the conversation. "They were here while you were napping yesterday and they set some traps. They'll be back in a few days to collect them. I'm sure glad you told me about them. ... Did you see in today's paper that the bar we used to go to is now an historic landmark? They are going to restore it to its former glory! Let's get the paper and look at the pictures."

As for the talking constantly without making sense .. nod, give vague indication that you are listening, like "mmm." And try to get away from it as much as you can. Leave the room. Listen to music on headphones. Put some music on that he likes -- maybe too loud for conversation.

This is a very tough role! Some days you do feel like you are going crazy. I assure you that when all this is over you will be sane. You can get through this! And keep firmly in mind that when it gets to be too much that there is no shame in finding an appropriate care center for him.

Also, get some respite! Taking breaks goes a long way toward retaining sanity!

I can't let my mother watch the news anymore because she has no sense of geography and every story is a crisis that is right outside our door.

She insisted I call the kids in rom outside because a black bear had been spotted (150 miles away).

Lock the doors, there is a rapist in the area.

And the latest...totally freaked out the other night about what we were going to do when the Syrians breach our boarders and try to attack us in our rural home.

And she does not just mention these stories. She dwells on them for hours, sometimes days. There is no logical answers that will convince her that her fears are unwarranted. I just try to reassure her that she is safe and wait for the next distraction.

My wife does the same thing. Can't win the argument. The only answer is I know the actors and the story. No need my getting upset over it. My best answers are no and it will be better tomorrow. : ))

One role the caregiver takes on in dementia is keeping the patient calm. You may develop a series of calming statements and use them (over and over). Depends upon the situation, of course but 'let's not worry about that now. Remember 'trusted friend' is taking care of that.' Or, 'I spoke with the police and they siad they solved that problem. Etc etc.
You might read the information on the alzheimers website (it also deals with other dementias) and they have many ideas there for such issues.
In addition, arrange for some time off for yourself. It renews your spirit and allows you to face each new day.
Good luck.

My father-in-law's hallucinations (visual and auditory) are becoming more frequent. He can't converse any more.  And his OCD cleaning behavior was beyond irritating. He can't (or won't) take direction or advice from us.  Several times I found him outside waiting for someone to pick him up and take him somewhere.  But at least that was daytime.  In the middle of the night, he was slinking around the house with a golf club in one hand and a flashlight in the other. Very creepy!  So we have started the process for him to go into a care home.  Meanwhile, the doc has prescribed an anti-anxiety med. It has calmed him down a LOT without turning him into a zombie.  We are still going  to move him  along though, as soon as a space is available for him.  We are sad that he has this horrible disease.  But we don't feel guilty that we need our home and our lives back.  We'll have had him living in our home for 3 years by the time he is placed.    That is long enough.

I had my mother prescribed something for anxiety. It helped a lot.
Also, if nothing I say to soothe her helps... I walk away and let her mutter and complain to herself, which she seems just fine with. And I don't feel a bit guilty. lol.

Is he on any psychiatric meds for agitation or Depression? You might do well having him seen by a geriatric psychiatrist who can prescribe or adjust medications.

I like to think of dementia ( which my mom has) as "broken brain syndrome". Just as with a broken limb, the broken brain is still partially functional, but the most important parts (logic, reasoning, being in " this" reality) are gone. Sometimes that results in agitation and upset. Meds can sometimes help.

Does he insist you participate? Or is he talking to himself? I'm just wondering what would happen if you sort of tuned him out, as one does with background music.

I agree about exploring meds for anxiety and depression. When my LO was so anxious and worried, it was due to her constant concern over imagined things. Like, if a person was well, hurt, lost, etc. She would obsess over imagined problems, some that she could not even verbalize. Medication helped tremendously. AND, I also learned to give her complete VALIDATION. Trying to convince her that she was not right or had unnecessary feelings, was a waste. So, I assured her and comforted her. No matter what it was, I would tell her that I had taken care of the problem. Everything was fixed. No need to worry anymore and that I was there to celebrate with treats. She was so relieved. This was calm her for a while. As the person's condition progresses, I think the talking about things in general decreases.

While he is in this stage, I'd try to get help so you can take breaks. It's not healthy to stay in that mindset for long periods of time. One person can only do so much. I'd explore ways to get help and time away from him for your own welfare.  
You say that he belongs in a mental institution.  I'd consult with his doctor and see what level of care that he may need right now.  I'd read a lot about what happens to the brain with dementia.  They aren't going to keep acting normally and have normal conversations.  Their behavior changes and I would prepare myself for much more than his odd comments as his condition progresses.

I, myself, suffer from anxiety and when it was at its worse---I know I was awful to live with (I was only 40!!) Everything terrified me, the poor kids couldn't leave the house w/o me stressing out over where they were going, etc. I TRIED not to verbalize my fears, but I couldn't help it. This came on after an emergency surgery and just my being worn out from 5 kids in a tiny house, too many responsibilities and being sick for months on end (gallbladder disease) and no one knowing what was wrong with my. Drove my husband crazy. I talked, cried nonstop for a couple of months at least!
Long story short, I have ALWAYS had GAD, and this just was the tipping point. Properly dxed and properly medicated, I am just fine. (Well, everybody has a day or two when they get a little kooky) but my point it, anxiety makes you fuss and worry--and drive others crazy. On my meds, I am just fine.
I think a good checkup is due for your hubby. You can be 'calmed' and not be a zombie. I'll be on this med for life, and that's fine.
Trust me, your dad is probably miserable with this-whether he can voice it or not.