Am I a bad person?

Backstory: There was this guy I had a crush on. We did everything together from going to dinner and hanging out to even working the same shifts (I got a job at my job). Fast forward a year. He told me he was upset because no one was ever gonna find him attractive, or wanna date him. I told him that I did and let all my feelings out all over the place (and it's not really easy for me to open up) and told him that I wanted to date him. His response; "Oh, I know." Three days later he started dating my best friend.So now they recently got engaged but I'm not happy for them at all. My best friend could do so much better. My ex crush is a liar and cheater. There are times when I get on Grindr, he's always on there and they've broken up more times than they've been together. I know my friend is angry with me because I didn't congratulate them. Am I wrong for not being happy for them?