At this moments I'm deeply confused, so please read my story and give me some insight if possible.

I'm a 16 year old male and I've been with this girl for a year. I've been obese, bad looking, a bit shy, boring person for my entire life.

October of 2015 I start dating the girl, she's really gorgeous in my opinion but has some real confidence issues towards her body, she could have been with way better guys than me, but for some reason she likes me.

Fast forward to August 2016 I start cutting, lifting and my height increases (and so does my confidence), now I have a body that is really close to the ideal male shape instead of looking like a meatball and start getting more attention and respect, not only from girls but from people in general.

The girlfiend starts acting weird and treating me like shit leading to little fights and that kinda crap.

Later I was told by mutual friends (and even suggested by her) that the gap of our sex appeal was something she wasn't cool with, and that she wouldn't like to be with someone who weighs less than her.

What I learned here is that sometimes some women need to be with ugly fucks to feel better about themselves and to look better to other people, maybe to attract another potencial partner.