Dad follows me around the house constantly and it's stressing me out. How do I get him to stop so I can have a few minutes for myself?

Many of us can relate! It's enough to drive you nutty. However, he doesn't mean to be doing that. Likely he's either feeling afraid or bored. You don't say if he has dementia. If so, he may feel fearful because if he can't see you he thinks he's all alone. You should talk to a doctor about this and see if something can be done to help him, if that's the case.
If he's just bored, then try to find things for him to do.
In either case, he may be a candidate for some time in adult day care where he'd have activities and you'd have some alone time.
Good luck,
Carol