When I was younger, I was not allowed many boundaries with my family--and in some ways I am still not allowed boundaries with them. I grew up and realized that other people were raised with an idea that they were allowed privacy, that their autonomy would be respected, and other things which were not so much an element of the life I had growing up. Boundaries were something which I had to learn to utilize as an adult. As the saying goes, there was no going back. I began with a simple exercise given to me in the classroom in an unrelated class. As goofy as the source is, the exercise presented in this article is very important. Try it.
Many disabled people are raised without boundaries. They may be told what to like, what to do, who to have as friends, who their peers are supposed to be or aren't supposed to be--the list goes on and on. Basically, if you grow up disabled, you may not have been given the option of personal boundaries. And even if you are able-bodied, you still may not have been given these or know how to enact them. That's where the exercise comes in.
You are allowed boundaries--but it may take a little while for that to sink in, and that's okay. Once it does, they become a very heady and positive force in life. YOU ARE ALLOWED THEM. Whether it's boundaries around not being stopped and asked questions about your disability or other marginalized identity, or just being allowed personal space, being allowed personal care staff who respect you, or doctors who respect you, or anything in between: you are allowed these things.
When other people don't respect that you are allowed privacy, respect, personal space, and a healthy-for-you environment, THEY are violating your boundaries. This is not your fault. People should always ask if it's all right before asking personal questions, violating personal space, making assumptions about you, giving you unsolicited medical or other advice, or a bunch of other things. People should ask if it's okay, or at least not assume that it is okay, because any of those things are boundary violations. And distancing yourself from people who violate your boundaries is okay. It really is. Maybe you explain to them--or maybe that doesn't feel safe. But if your boundaries are violated, you have every right to uphold the boundaries you've decided on. It takes practice, but it's worth doing. After a while it becomes second nature, and upholding the boundaries is easier and easier.
New scenarios will present themselves, but at the end of the day your boundaries are there to protect you and honoring them is the same as honoring yourself. And it can be done. I promise.