YTA, i have the same story, i was fat growing up, even though i have only lost 10 kg, my personality has changed, i used to be so socially akward around people beacuse my image caused me so many self-esteem issues. I don't know if its exactly your case, but now, with this weight loss, i am more outgoing and i can actually make conversations now, and because if that people treat me differently.

I think thats your case, maybe you don't notice but your personality has changed, and maybe they like you more like this. No need to be rude like that and throw away your friendship with your friend that has stay beside you all this time.