From my own experience pills are useless by themselves, I've used a variety of benzos, tranquilizers, anti psychotic, ssris and other drugs mixed to attempt my past suicides. I've tried 2 liters of vodka with more than 100 pills of clonezepams and dozens of quetiapines, mirtzapines etc. also took anti vomiting drugs (or however they're called), took me 5 days to regain consciences in the hospital with my entire stomach content pumped out of me. Best method would be using a weapon IMO, or hanging, I wont go into it, but there's plenty of information on this site on how to do it. Best of luck.