emotional detachment from father

I (19f) made another post in this subreddit about a month ago. It was a newspaper article about the man who murdered my grandmother, it mentioned him as my father. I finally asked my mom about it a couple weeks ago. What I saw in the newspaper was true, the man is my biological father. I didn’t particularly feel that much emotion when finding out, I was more relieved that it was out and done with. The new problem is that I feel an emotional detachment towards my actual father, the man who raised me. We’ve never been that close, I’ve always gravitated more towards my mother. It just feels like all my love towards him was there because I thought he was my biological father, and I should love him. Now that I know he’s not, it’s vanished. Is this normal? I feel like a loser having to keep asking Reddit questions regarding my life but, I don’t have anyone else to discuss this with.