From what I've been reading all the way back to that racist incident at work (was that you? I'm not remembering wrong?) he has been neglecting you, taking you for granted and being insensitive towards you for a while.
It may be that he does still care about you, but all of this, as you point out, came up when he took notice he might be losing you. Sadly, that is the way with pretty much any of us, about different things: not appreciating what we have until we lose it.
If it was me and, of course, you are not me, this whole thing would be a too little too late on his part. And what's not to say that if you give him another chance he won't return to neglecting you?
But, I don't know him, you do, so what to do is up to you, naturally.
I'm sure that he was good to you for quite a while, but things seem to have deteriorated in a rather permanent way.
In any case, whatever you do, I would advice against the lashing out behavior and the things you're doing to purposefully hurt him. I know that you're hurt yourself and that hurt is justified but repaying pain with pain is not the way to go. It will ultimately do YOU no good, especially since you are still sharing a household with him.
Stay strong and do what is best for your well being, mental, physical, emotional.