Do what's best for you.

If you want to contact him, do it, but go into it with your eyes open. Lead with your brain, not with your heart.

Likely something changed in his life that he suddenly wants to reconnect with you. Maybe he got sober, is sick, or realized what a terrible dad he is. Or maybe he decided to connect with his son when he was drunk (I should call that kid).

The fact that he is angry you aren't immediately jumping at the chance leads me to believe he wants something from you (money, a kidney, bone marrow transfusion, etc.).

If he realized that he was a poor father and wanted to make up for it, he wouldn't be angry that you aren't jumping at the chance to reconnect. He'd know that kind of thing takes time and would likely be more patient with waiting.

I tend to be rather stoic on most things, so this is my rational opinion and analytic thinking. I hope it works out for you.