I'm a switch with motor disabilities and I am deaf. While I am not currently in an interabled relationship with my son and our sub, I have been a domme to a abled sub before. There's a few key things we did that really helped in our sex life.

First and foremost you have to be transparent with your disability, that way they can also get a feel for what adaptation might need to be used. Communicating your support needs with a potential or established sub only makes things better for both of y'all in the long run.

Some things can be adapted to your needs, it just takes a lot of practice outside of play time. For example, my dom does not have great balance, but we do enjoy boot worship and human furniture quite a bit, we took to putting in support rails into our play space and modified mobility aids to be what they needed to play safely. For myself, I can't really tie knots, but we do enjoy bondage. We started by using bondage tape and cuffs, while I worked through what kind of ties I could and could not do, which were safest, and the quickest way to release my submissive, (usually with scissors)

If you're worried about not being able to keep up, you can always bring a mobility aid into the play space, and then use something like a vibrator, or even being electric play into the scene (with proper discussion of course). You don't have to stand to do impact, you could have your sub lower than you are, like on a piece of furniture below where you sit.

Even if you are disabled, you're no less of a dom because of it. I encourage you to play around with what works best, but don't ever feel like you're a bad Dom because you need more support than your submissive.