I can hear your pain and desperation but let us get one thing straight, you did not cause this by doing so much 'bad stuff' this isn't payback for anything you have done so get that idea right out of your head!! You could have led a quiet virtuous life (;) and still ended up where you are right now and I don't think your parents are helping you in the slightest!
As for the disease itself, unfortunately there isn't a cure(currently) but that isn't to say that things will not stabilise and allow you to live a near 'normal' life. Sometimes drug combinations are a bit hit and miss and what works for one may not work for another but in time they will find a drug/drug combination that gives you optimum relief and will allow you to get your life back.
My son is 18 and has crohn's and after trial and error the drugs he is on have got him in a good place. Yes there are the odd days when he doesn't feel 100 % but on the whole life is normal-he parties and drinks, plays sport etc
As previous poster said Hang in there :)