Your friends are absolute arseholes. I mean, wow. How horrible. Honestly, I think it's your friends you need to ditch, not Insta. Also, you look fantastic in that swim suit and that's amazing flexiblity too, I struggle to tuck my legs under myself like that now (I am 53). I also have large bosoms and I wish I looked half as good as that.
Fuck all of them, and their little dogs too.
I very rarely say that women are just being jealous. That's just a myth society pushes every time a woman says anything vaguely negative about another women. But, honestly, I think maybe there is some jealousy there, because you look genuinely great.