please help me

I made a mistake of having unprotected sex, I’m 17. I have pcos and plan bs mess me up really bad. I also have anxiety with medicine. he barley came in me but I peed and rinsed my vagina in the shower I know I should just take the plan b but I’m scared it messed me up bad last time and I just got off a 30 day period ( period wasn’t from the plan b)