No judgement at all from me on any of this. Life has all kinds of surprises in store for each of us, though I am sorry that you're the one who's suffering from decisions you had no part in. My own mother found out that the man whom she called "Daddy" her whole life wasn't really "Daddy", but unfortunately found out after all the involved parties had passed on. This knowledge wrecked her for years.
If you did want to find your biological father, your best bet might be something like ancestry, but in the current climate of neo-racism, such platforms are not without risks.
In any case, we rarely comprehend while in the throws of our youth elixir how some of our seemingly impetuous decisions can have lasting consequences down the road. Just try to love, forgive quickly, and don't completely ignore thefootprints you are leaving in the sand. In the words of Earth, Wind & Fire, "It's All About Love."