What is it called when I only feel extremely positive or negative emotions for days at a time?

F20 - I know it’s not normal bcuz because i didn’t feel like this until I was 18, the feelings been getting worse and I cant escape the cycle, every time i’m happy i just know the fall is going to be so bad and then everything around me falls apart, if i’m having a bad few days then they’re entirely bad, if they’re good they’re great I feel like the world is all mine. When i’m in a good patch I am aware it’s just a patch it will end soon but when i’m in a bad patch i feel like i’ll never get out of it

I’m 163cm tall, on no meds