22 years of lies 😔

I found out today that the man I thought was my biological father is not. I am so blessed to have had a man who stepped up in my life and loved me like his own when my "sperm donor" didn't want me. However, my mother threatening my father with telling me while they were fighting (over their divorce) was not the right way for that to come out. I'm so heartbroken right now. 22 years they've held this secret from me. I don't know how to feel.