I want to die now that hes left

My bf broke up with me cuz i smoked a cigarette?? And i knew that was one of his dealbreakers cuz hes just super super against smoking and finds it disgusting and does not want his partner to smoke and he told me this at the start of our relationship but then last weekend i got blackout drunk and took a puff of my friends cigarette and he found out and just ended it on the spot. I just feel like our relationship meant nothing to him if he could just end it over something so stupid i feel like if he truly loved me he would be able to look past this one mistake and now that hes gone i really have no one cuz all of his friends were my friends and now i lost all of them too and i have no one and i just want to die i feel like ive lost everything