Death Should be invited In?

I Myself have been secretly depressed when alone its not because i dont like being around people its just that i dont feel like anyone needs me around. Today is the 30 and my friend who passed away almost a year ago’s birthday is tommorrow and i dont think that im going to be able to make it more than a couple more days. I cry once so every often hard and i tend to smoke alot of cigarettes when i do. Ive done everything seen a therapist, taken medication which led to an abuse problem and ive been cleen for the last 5 months off these meds but i feel like i should just go. ?  Am i just being selfish or what i need help. Someone just please help me come to an answer.