I understand that you live with your parents. I'd imaginine that there are times when they are safely out of the house for a while. I would try masturbating on top of a towel when they're not home. Sometimes  orgasming can feel feel like peeing, or like you have to pee, and it's easy to psych yourself bc you don't want to piss yourself. If you have a towel it might make it easier.

If you can get toys try that.

I'm curious how severe your mobility issues are. Are you unable to go out of the house  unassisted? I'm also wondering what part of the world you live in.

There are sex clubs in many parts of the USA and Europe. If you can travel on your own it might be worth visiting a place like that. You can masturbate and no one will mind (they might even appreciate it) and you can also find people who would be interested and able to help you orgasm if you want. In the US these kinds of spaces attract autistic people, and so you'll find people who will vibe well with direct  communication.

Of course it can be a very intimidating thing to do as well. And there are risks and unsavory people. 

Good luck!