<Snipped quote by Techspert>
If that was as you claim, he would not be able to speak, decide, or even function without your support. But as it stands he is still himself and can still make some choices on his own. So although you are indeed supposed to be a support and safety net for him, it does not mean that he should have to rely on you completely.
After all, I am not asking you to leave him or stop caring for him. I'm asking you to take a chance that might help him make another step forward without losing what he cares for.
*Shakes my head*
He was never a vegetable. But he needs support now more than ever, and I can't ethically leave right now unless he asks me to.