PLEASE!!! young & infertile?

im 17 and i get scared when i see cute babies that i wont be able to have one some day. i had for the first time at age 15. i smoked for three years..i was bulimic for not too long...i had really bad kidney infections...im on asthma and allergy medicines and used to use inhalors A CRAP load. and im just so scared this will all come back to me and i will fall INFERTILE. did any one else have this and was fine? and i took extasy a few times.. and i used to drink alot. but ive been sober for a year. urgh im just scared!! anyway my period cycles are like anywhere from 45 days long. to the last one which was 80 days long. if i get on birthcontrol pills for like 6 months will this regulate them to the point where even when im off them i will be regular? my brother and i werent planned so i guess that means my mom was pretty fertile and my gma had like 6 kids. help!!!