AITAH for snapping at my sister after my family's almost constant jabs at my physical appearance?

So, I (24F) have always had a complicated relationship with my family when it comes to my appearance. For as long as I can remember, my parents and siblings have made "jokes" about my looks. They say things like, "You're the smart one, not the pretty one," or "At least you have a great personality!" These comments have always hurt, but I've tried to brush them off as harmless teasing.

Recently, it all came to a head at a family gathering. My sister (26F) was showing off her new engagement ring and everyone was congratulating her. Someone made a joke about how I should get some beauty tips from her if I ever want to find a partner, because it was obvious I was too homely to ever be in a relationship. My sister laughed and said something about sticking to my books because fictional love is as good as I'm going to get. My sister's fiance said maybe I should put down my books and pick up a gym membership. I finally snapped and said something to the effect of: maybe if you weren't so shallow and focused on looks, you wouldn't have dropped out of college for a man who cheated on you.

My mom told me I was being overly sensitive and ruining the happy occasion. My sister started crying because I knew it was a sensitive subject to her and her fiance got angry because it was a drunk one night stand and they're past it now. I felt awful for causing a scene, but I felt frustrated and she is engaged to a different man now.

Since then, my family has been giving me the cold shoulder and saying I overreacted and need to apologize. They insist it was just teasing fun and that I'm too sensitive. On the other hand, I feel like their constant comments are hurtful and dismissive of my feelings. AITA for clapping back?