Damn what a "happy story" your shit father that fucks over your life all the time just happens to not be your real father freeing you from any relation to such a trash human and making revenge a moral choice at the same time. Him not being the real father is like winning the lottery.
Real talk but this kindoff happened to me actually, my grandfather wasn't actually my mothers father so I could rightfully scorn him and stay away till the day he died after finding out, though I haven't seen grandma for a long time because of it sadly, but shes not dead so thats nice. Anyway point is, this shit happens, maybe the person isn't just an arsehole, maybe the fucker never actually thought of you as family in the first place.