I think you're already halfway there, seeing that you want to.
It's just that you're still raw from the experience and the emotions are still running high that it is difficult to picture yourself forgiving him.
Best thing I can say is you need to accept that he is like that and will likely stay that way (and there will be a lot of forgiving to do in the coming years) and the only thing to do is to love him, despite his flaws.
Sweetie, My dad was, and still is horrible to me. I had to just accept he hada severe mental problem, and I was fine.
For first, you ignore what they say. Then you listen to yourself. What do you want to do? Then realize. They generally don't mean you harm. Just deal. Use a crowbar if you have to. You may be crazy, but they are worse.
My dad was the same. He said and did horrible things to me. I forgave him over time, but it took AGES! Yes, people say horrible things when they're angry, even me. Something I picked up from him that I'm trying to control.
All I can say is just ignore him. He's the one with the problem. **** him hun!! Keep smiling and telling yourself you're fantastic. Otherwise, why not tell him how you feel? Maybe he'll realise what a **** he's been and apologise. Can't hurt to try.
In all the things my dad has done to me, there is one thing I have NEVER forgiven him for, and that calling me a liar. That hurt more then any of the beatings he gave me.
Why should you? People let the truth slip when they are angry. What you do is set it aside and continue on with your life looking forward to the day when you can get out on your own and not have to put up with any more of his or any other controlling persons crap.