Sorry--I'm unfamiliar with your story. I am not getting how they can get into your house? Do you not have the option of keeping them out? My home is my sanctuary, and there is no way that I could be that uncomfortable in it. You have helped to turn yours into a warzone. Where do you ever find peace?
Keep in mind that none of this is normal. Also, recognize that you play a part in this dynamic. I'm not blaming you, but empowering you to make some very necessary changes. There is something in your personality and the way that you interact with them that tells them that how they interact with you is perfectly fine. There is no reason for them to change. There is something (in your subconscience?) that is benefitting from this foolishness. If your children get it, then they can be your allies.
There is nothing petty about your post, but let me say this: If you were my friend and I was hearing this from you, it would really work my nerves. I would be annoyed by YOU, and I would tell you so. So what if they stop by and ask you anything? Do you just have to answer?? People can ask me anything they want, but I am not obligated to engage. I have a pretty good relationship with my mother, and she knows that if I don't wish to participate in a particular conversation, then I simply will not. "That's not a conversation I want to have." You have a right to say that.
Your parents can come to pick you up if they want. You can be there or not. You do not have to go with them. If they block you in, call for a tow. They would be doing it to themselves, so you don't need to feel guilty.
As far as your hospital stay, they dont' have to have access to you, even if they know exactly where you are. You can alert the staff not to let them into your room, in the event that they learn your room number. I have seen it, and it really is no biggie to them. Put restrictions on your visitations by giving them a list of acceptable--and unacceptable--visitors. They'll take it from there. At least you can have a peaceful recovery.
If it's not reasonable for you to block her calls, start hanging up on her when she starts to scream. You are a grown-up, right? With your own grown-up kids? Get yourself into therapy right away, so you can get some tools for dealing with them. It's high time, man.
ETA: Just read your SWH. Fix the door. Get an alarm system and set it. Call the police. If you can't afford to fix the door right now, cover it so that no one can go in or out through it at all. Turn it into an essential wall, until you can use it as a door again. Seriously, this is cuh-razy.
Even if your kids come to hate your parents, they're more likely to see that personality type as strong and yours as weak. It will affect who they become as adults. They'll love you but will ultimately not respect you, because they'll determine that being like you won't get them anywhere.