AITAH for ending a friendship after comments about my weight and splitting up the girls' friend group?

I (28F) have a college friend group of seven girls, all the same age. We’ve been pretty close for 10 years, going on trips together and more.

Two years ago, one of the girls, Mary (28F), announced over dinner with the group that she and her boyfriend had set a date for their wedding and that the proposal was coming soon. We were all so happy and excited for her.
Toward the end of the night, Mary told me that I should lose weight for the wedding because I had gained some.

It caught me by surprise, so I didn’t say anything and just ignored the comment, but obviously, I was very hurt. I knew I had gained weight over the years (160 lbs at 5 ft 6.5 in); I have a mirror, but I never thought it would bother her.

For reference, I’ve always been a normal weight (135 lbs at 5 ft 6.5 in), but five years ago, I started gaining weight and couldn’t lose it no matter what I tried.

I am currently 167 lbs (5 ft 6.5 in) and was diagnosed with PCOS and insulin resistance three weeks ago, which turned out to be the cause of my weight gain despite eating 1,250 calories a day and working out like crazy to lose weight.

Anyway, I was hurt and cried a little on the way home, but I just let it go.

Fast forward a few months after the engagement: we went to dinner with the girls, and my food was taking a long time to arrive. Everyone else had already gotten their plates and was eating. I made a comment to Mary that I was hungry and wanted my food to arrive already. She replied that it would be better if my food never came and I missed dinner because I was getting fat.

Again, I let it go at the moment because I didn’t even know how to confront people. I was very ashamed of myself and offended. I just went home and cried.

After a few days, I decided it would be best for me to distance myself from her and stop being close friends. I was too embarrassed to ever tell the other girls about these comments. They only know that I don’t feel comfortable being around Mary, and this has caused the group to drift apart a lot.

So, I basically broke up the friend group, and I feel guilty about it.

So, AITAH?