I say this gently.....smoking pot is not helping your depression, it is making it worse. It just does, no matter that you feel differently. I did the same thing with alcohol, drinking "socially" daily sometimes getting drunk. It made my depressions so much worse. I don't believe pot is as bad as opiates and hallucinogens. But does it have to be that bad? Smoking cigarettes are no good, drinking is bad for your mental health, and smoking pot certainly is. Plus smoking pot is ruining your lungs just as if you were smoking cigarettes.

That being said,

You're right in that you can only tackle one problem at a time. If you tackle the pot first, it makes it easier to deal with the depression. Right now you are just shooting yourself in the foot. Give the group a chance, and see if it helps in even the tiniest way.

I say this as someone who has had issues with substances, primarily alcohol. Now I am an alcohol and drug counselor. And I am the healthiest mentally I have ever been. I wish you all the best, however it works out for you, and whatever you decide to do. I hope you haven't been offended. That is not my intention, I just wanted to give you a different perspective. Something to think about.