Why do I keep oscillating between hating and loving the way I look?

I almost always hate the way I look in school. Then I get home and feel hot as hell. Then maybe a couple hours later I’ll feel like a mountain-dwelling troll. Then I wake up and feel pretty again.

WTH is going on?? It screws with my mood so much and I have no idea what’s happening. I can only assume I feel pretty when my hair curls prettily, but that seems like a stretch?