Can somebody help me?

Alright guys, for those who have a heart, im begging you please read this and give me positive feedback, you guys dont know how much this would help me. I am an 18 year old male with severe OCD, graduating highschool this year, and lately im falling into this deep dark hole that I cannot get out of. When I was back in 10th grade, I used to have alot of friends, now I have sectioned myself of from socializing just to save myself from obsessive thoughts. My friend Ray and I have been friends since we were just kids, then he started dating this girl named amber (and she was a very weird/smy person) ever since then my OCD came out. I look back in such regret because I hung out with those people who I didn't like, it even ended up with me being stuck at a "drag queen house" where one of them complimented me on my looks and it bothered me so much that I thought about taking my own life, mostly because I smoked a blunt with them and I thought I contracted gay germs. Ever since then I havent been the same. My girlfriend of 2 years left me and now looks at me like a failure, and like I said I dont have anymore friends really, and I think my mom is the only one who notices. So because of my OCD, whenever I go around my friend Ray or other I dont like being around, I throw the outfit I was wearing when I was with them in the garbage, because its "contaminated". Now I look back at all the things I did (smoke weed, hang out with people who were complete ss who are going nowhere in life) I think it has limited me to thinking im going to end up like that. Once I graduate, I planned on going to school to become an X-ray Technician, but now lately I dont want to because I think im not good enough anymore. My grandma has become my bestfriend these past couple months, today was her 78th birthday actually. Whenever I go into these episodes of "contamination" I feel like I infect my grandmother and my mother who are clean people, just like the other day when I ended up at a section 8 apartment complex, i thought I infected my clean house and my new Apple iPhone.. I just cant stand the positions ive been put into and my compulsive thoughts, Im ready to hang myself to get away from the agony of it all, I feel as if my lifes already been put to waste anyways.. Thank you for the people who have enough heart to write back, it means the world to me - David.