My husband has dementia, is incontinent and now has parkinsonism. Back in Feb he "just" had dementia was able to walk on his own.

It may be that your husband has Lewy Body Dementia. I suggest researching LBD and have a motion disorder specialist or a LBD experienced neurologist manage this issue.
Exercising to music with a fast beat, may improve his walking. May God bless both of you.

A few things-consider getting a consult with a movement disorder neurologist to confirm that he has Parkinson’s, not a Parkinson’s plus disease. There are some closely related diseases that are very fast moving. It’s important to get the right diagnosis. If he’s falling a lot, you might need to switch to the wheelchair. I would recommend a hoyer lift. It is doable if you have some help at home but it isn’t easy. The neurologist should be willing to prescribe physical therapy and that might help a bit with strength and they can help you learn some techniques for transferring him. I use a gait belt and that helps. If at some point your husband qualifies for hospice, you will be able to get a home health aide that can help you. Parkinson’s usually doesn’t progress super fast so I think starting with a movement disorder neurologist is key in case it’s not Parkinson’s. You can do a google search to find one in your area. If there aren’t any, ask the neurologist if there might be another neurological disease at play here.

Oh, I'm so sorry to see your news. It must be incredibly stressful. I don't have any experience with Parkinson's. I have read that it can progress at varying paces and you never really know how fast it will progress. Have you met with an attorney to discuss financial issues? I might also check to see if the Parkinson's association would have a referral to help with planning and options for help and care. I'd do it before things are too pressing, so you will have time to think and sort things out.

I am also sorry you are going through this. My stepdad had 2 strokes and then Parkinson's all in his late 60s and it was very aggressive. My mom did everything for him - including moving him from bed to wheelchair to favorite chair and back again. Plus in and out of the car for doctor appts. My best advise for you, if you aren't yet willing to move him to a facility, is get help. My mom wouldn't accept anyone's help. Even after hospice came into the home, she still did everything for my dad. The only time she'd ask for help was when he'd fall and she'd call the EMTs. Help is important, more so for you even than your husband. Check with your local agency on aging. They can provide information and assistance.

I'm sorry you're going through this, I went through it with my father. What happens is you go day to day where you think everything is OK and you and he are able to manage until all of a sudden you realize you can't and you need help and help fast and that kind of help is not so easy to get. He is going to need a nursing home, and most likely needs one now. I'm sorry. If you don't have anyone helping you with that process, it is very hard for most people to navigate on your own. If you're unsure what to do, please keep posting and the great people here can help.