I applaud your personality. It seems your heart is glowing with love and forgiveness, a rare trait after being mistreated by a piece of garbage like that. However, don't let yourself be a doormat. If he calls you to verbally abuse you, why not block them? Change your number? You can forgive his actions, but don't be pushed over and continue to be hurt by them. It's great that you're looking out for him, but I would suggest removing yourself from the relationship once you find out what's going on.

Finger slipped, sorry for pressing YDI.

I didn't have the greatest relationship with my dad growing up either, but he died 3 weeks ago, and I miss him like crazy. We never know how much time we have in this world, so use that time wisely. Try and reconcile.

I... don't know how to properly respond to this...

it's America get a gun to see if he's OK when he starts belittling you and you've had enough be glad you had your trusty side arm to dispose of him, in stead of going home and cooling down.

call him and address him harshly if he replies. he might feel.

You feel that way because you're a good person, OP, and that's a wonderful thing. Your dad's time will come as it does for everyone. You may feel bad (survivor guilt is a thing, and so is neurotic guilt from abuse) but you should know you have nothing to feel guilty about, ever, even if you wish him dead every single day.

So instead of calling the police or relatives close to him, you post an FML.

You've got a big heart OP. But if he is dead, after a while you'll be quite relieved.

You are truly a better man than I, Gunga Din.