What do I do?

Hello! I've had a friend whom I've considered one of my closest friends for the past two years. However, there are things she does that make me upset. She always treats my relationship history as a punchline and I try to play it off but it really bothers me. For example, this guy I was best friends with asked me out in February and I said yes because I had the biggest crush on him. A few weeks later I found out he was cheating and it absolutely crushed me. I told this friend about it and all she did was laugh and make fun of me. I was hurt but I decided to drop it. A few months later, I fell really hard for this guy at our school. We talked for a while but he suddenly ended things some random morning. I was taken aback because it was fine the day before and we even made plans to hangout the day he ended it. I was upset and when I told my friend, she treated it like a joke. She knew how much I liked this guy but all she did was laugh every time we saw him and basically told me I had it coming. I tried to ask her to stop but I am genuinely horrible at confrontation and I am terrified that our mutual friends will think I'm being overdramatic. What do I do?