i need help

hi. i just turned 23 years old and i have trouble getting a erection. im in the best shape of my life. i run 3 miles a day i lift weights. and i do mma . i told one of my friends about my problem and he opened his mouth and now every1 knows. i get mad fun of all the time and lost all confidence. i used to smoke marijuana.i occasionaly smoke ciggerattes. i do not drink .and i feel that maybe being 6 feet under would be better then living. i did nothing to deserve this . all i do now after i work out is just stay and my room . is there any help for me or am i a lost cause?