Feelings ugly lately

Idk why but I’ve been feeling really ugly and fat lately. I feel like I am the last choice and a shadow behind my best friend because she’s so pretty. And I try so hard to look good and take care of myself. Nobody notices. I feel like no guy likes me. I’ve lost my appetite bc I feel fat. My period hasn’t started for a while so that could be it. How do I get out of the funk?