I think my boyfriend is depressed...

My boyfriend told me a long time ago that he used to take antidepressants and he showed interest in wanting to get back on them. That was back in July 2014. He hasn't had insurance in idk how long but I know he's working to get a plan before the deadline. I'm just so scared for him because I just now pinpointed why our relationship feels different.

- he's irritable

- he's always tired

- he shows little to no interest in sex. We went from having sex 4 days a week to 1 day a week or every two weeks.

- he's got constant back pain

- he's obsessed with work

- he made a joke last week about how he hates himself

- he's stressed

- he feels pressure from everyone (me, family, work)

I'm just really scared because this isn't the man I fell in love with. I'll do anything I can to help him, I just don't know where to even start! How do I even go about telling him that I know he's relapsed without emasculating him?? I know depression just makes men feel weak, like they aren't real men.

Help please :(