Yikes, that's harsh, but it sounds like you're doing what's best for you. If you are looking for ways to become less dependent on your son, I would start with community resources, meaning search for your closest disability resource center, and if you're in a metro area, it might even be specific to people who are blind. Let them know what life activities concern you and hopefully they can help you address those.

I'm very sorry for your loss.
Being married myself, I can't imagine how awful this situation is for you.
Have faith in yourself and your ability to get through.

I am divorced. My children were younger and there was a nasty custody battle which ruined me financially. Even after we divorced he continually undermined and harassed me. I finally took the kids and moved to Texas. My only regret is that I didn’t do it sooner.