I know this is gonna sound a bit harsh, but sometimes, you gotta walk away. You can't help someone who doesn't want to be helped. And if this person is aggressive towards you, then perhaps walking away is the best thing to do.
You are NOT responsible for what he may or may not do to HIMSELF, even though we like to think that we can help.
I once got a complaint from a customer at work, for being too happy! Sometimes our 'light' is too bright for those who are still stuck in the dark. And if you are starting to dread having conversation with him, then my suggestion is: don't. Don't keep putting yourself into a situation that makes you so uncomfortable that you are feeling dread and anxiety.
In the meantime, while keeping a distance may seem harsh, perhaps you could also tell him that when he is ready to treat you with respect, and NOT be hostile and critical of you, THEN you will help him again. But remind him that you are not his enabler, and you will help him, only if he agrees to also help himself and get professional help.
Also, remember we are here for you too, for as much as you like.
Take care. I'll be thinking of you. xo