I'd tell him that I understand that he's going through some things, but it's unfair for him to rely so heavily on your gf for weed. If he's that down in the dumps, try to advise him on how to get his life back together-that should be his number one priority, not bud. It's not your gf's...
I don't have a problem with people calling it pot, but I can see why others would. I never used to call it "reefer" until I met my boyfriend, cause he calls it that. I kinda like calling it that now, it grew on me, has an ol' timey feel lol. Usually though I just call it weed...