Set boundaries brother, I live at home and butt heads with my mother. I'm on my way out as well. If you are empathetic learn to shut that off while around your dad, his problems are not your own. Don't internalize or personalize em.
Things that i've done to stay sane
-Keep to myself in general
-Carry my own weight
-Do not allow any chores or things to be done around the house not by you, less you want covert contracts on behalf of your pop...
-Divide up your space, keep distance between your dad and you
-Get out of the house whenever necessary, seriously anything man. Go out, walk, jog, drive, library whatever
-Avoid confrontation at all costs, be cordial as possible even when you're in the right.
-Pay for your self at every opportunity you can, rent if needed.
-Get yourself into a physical hobby or hit the gym, best thing for me when i'm po'ed is angry lifting
-Therapy
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I feel ya, hang tight and keep doing your own thing and get outta there when you are financially able. Also, if you're not meeting your own needs make sure you get on that. No More Mr. nice Guy is a good book for that if you haven't read it.