Down in the dumps

Lately I've been having an overwhelming feeling of not being good enough. I feel not smart enough, pretty enough or fit enough and just very insecure. It makes me feel really sad all the time, anytime I see another girl I automatically feel like they're better than me and stuff and idk why it's just really problematic. Maybe it was brought on because I'm struggling in school rn and financially idk. Any advice?? 😢