I don’t agree, OP that even with all the advice you are receiving here, that it will be at all easy for you to make a decision and act on it, to eliminate the abuse you are suffering.
And it is abuse. Why should this be allowed to continue? Only you can stop it. I assume you just need to offload this situation, without too much identifying detail, but family and friends are out of the question and it’s hard to know where to turn.
So, where to start? I think before seeking some professional help to assist you with the fallout to come, you must stop playing. If you’re no longer part of the sick game that this person feels certain you don’t have the guts to stop, then show them you damn well do! Tell them, no more, they’re blocked. The end. This is obviously someone close who feels they’ll be able to play mind games indefinitely. A Son, I’d imagine, and someone who’d feel safe that his Mum could never shut him down.
Shut him down. You say you’ve been really ill. You must care more about yourself and start to build a better situation for yourself and stop living in hope that this person will suddenly have a Road to Damascus moment. He/She showed they could only do that when they felt some panic at your hospitalisation.
After blocking, then find a good Counsellor. Start to rebuild your strength and resolve to not be the abused. You’re worth more than that. Stop being reliably compliant/hopeful enough that things will change when only you can change them. It’s then that this person may have a good while to reflect, regret, seek help. Who knows? But in the meantime you’re not enabling your abuser and the torment will stop.
I wish you strength and I wish you well. 💐