Anyone else get very upset with their loved one but then ask how can you get so upset if they have dementia and do not know any better?

Everyone loses it sometimes. As a caregiver in the dementia world it's inevitable. A burst of anger can be caused by frazzled nerves (stress), frustration, grief or some other trigger. How often do you have to tell your LO what time it is before you have a meltdown? A dementia caregiver doesn't have a “manual of caregiving” that states how you would address every situation that presents itself. If one did exist, it would be different for each caregiver. You say you're learning the basics of caregiving. There are some good resources that can help you in this endeavor. Besides this forum, Grandma and others have already offered some excellent help, there are numerous books, websites, and YouTube videos that can speed up the learning process. Three of the most helpful books I have read are “Learning to Speak Alzheimer's”, “The 36 Hour Day” and “Surviving Alzheimer's”. Although your dad has VaD, all of these books address behaviors common to all dementias.

I think that ANYONE that says they have not been angry, raised their voice when caregiving is lying.
You can't help it.
You apologize, you forgive yourself (that is the important thing) and you tell yourself to do better next time and you move on.
If you find that there are more times you are angry, frustrated, upset than not then it is time to 1) get help in OR 2) consider placing your loved one in Memory Care.
Unlike with a child that will learn and mature a person with dementia will not learn, will not understand and will decline NOT mature.
There are things you can do to help yourself.
First you must realize you can not argue with someone that has dementia.
Their reality and logic is theirs not yours.
When you find yourself getting frustrated if it is safe leave the room, walk away, do something else.
Change the subject. Stop the focus on the "thing" that is causing a problem.
(this next one is going to sound strange but it can work)
Laugh. totally unexpected reaction will change the focus of what is going on. And if you think about it many of the things that cause frustration are silly things so laugh about it.
Obviously if safety is a problem you need to do what needs to be done to keep your loved one safe and you safe.
(by the way if the fee is a charge you might get this reversed contact your credit card company. If it is legit and you want to cancel you might be able to particularly if dad is not cognizant to enter a contract.)

Yes. I was sooo angry.

I think it’s part of the grief process. My intelligent mother was doing things that JUST DIDN’T MAKE ANY DANG SENSE.

It wasn’t until she moved from mild to moderate decline in her dementia when it finally changed a bit, and I wasn’t SO angry. I’m still angry a bit, though! I think that it’s normal, from reading here on this forum.

I was so angry at first. Pissed off that all our plans for retirement were shot. Mad as hell that my brilliant, creative husband couldn't figure out how to put his shoes on.
Realistically i knew he wasn't doing it on purpose, but until I acknowledged that I was angry, nothing helped. I have a wonderful friend, who has gone thru more family sorrow that one person can have, who told me to say out loud, I am angry at what has happened and I acknowledge it's not his fault. Then every morning, ask for grace to have patience and compassion with him. And that helps. Sending you a huge hug because it's a hard journey.

You must realize that arguing with or trying to get cognitive, lasting understanding from a person with dementia are both fruitless endeavors. Your father isn’t able to make solid decisions, it’s frustrating for sure, but he needs compassion and support. Accept the reality of who he is now and decide if you’re up for caregiving in that reality. His thinking and world are slipping away, how scary for you both, I hope you’ll find a path that helps you accept this and move forward in peace