Alcohol and weed can affect moods. How are you going to manage to get a proper treatment regiment from a psychiatrist, while still participating in this recreational use?

Have you considered making a list of what it is about this relationship that feels right, and what about it feels wrong for you, as a person? You are scared to break up, with him, because he's already professed, when it's done, you will no longer be in contact. You mention, he has a way to calm you down, and see that he's right about staying together and your 'wrong' for wanting to break up?

I'm more interested to hear more, about what brings you to the point of wanting to end things with him. Not convinced it's due to your moods? What brings on these depression 'moods' that leave you feeling you want to break up with him?