menstrual cycle is wack, advice, help

Desi
I'm 19 and I have the worst menstrual cycle.
I get it for a month or two then it skips for as long as 5 months. Now I've tried primrose oil to try and regulate it that doesn't seem to help, I've asked my sister if she's ever been this way and she said yes, also I don't know if it's my cycle trying to sync with my mom when she doesn't have a period anymore. I need help. Has this ever happened to anyone?