Medication I think might be something to try again, how about starting medication and keep smoking for a month to give it time to kick in? I mean I'm not going to suggest you stop smoking if you think that's what is keeping you from being catatonic or from committing suicide. If you are medication resistant you might want to ask you doctor about ECT. I know a couple of people who have done that and it's helped them a lot. You get treatments often at first but then they reduce it to maintence visits. I have heard weed can make people depressed. It's a hard situation since you feel so bad. It really sounds like your self medicating, think of someone in your situation who uses alcohol instead of weed. But even telling alcoholics to quiet cold turkey isn't safe, hopefully you can have another meeting with your doctor? Also I didn't read that you have seen a therapist. Therapy is a big part of dealing with depression, even if meds don't work therapy might. They can help you a lot with anxiety and on how to meet people. I recently made several friends all thanks to my therapists suggestion to try going to some social events for shy people. I hope you feel better, I know you are suffering and you are doing your best. Hang in there and don't blame yourself.

PS: I don't mean to discourage you but I too want to be happy but for me I have realized that I will always have a degree of sadness and hopelessness in my life. Everyday I have suicidal thoughts and urges. I have come to realize that for me true happiness is only experienced in small short bursts when I can forget my pain for 30 seconds or if I'm lucky a few minutes.