Tl;dr: I can't tell if I don't love my gf because I'm depressed or because I just don't feel that way about her. Help

So I have had escalating depression since I was, maybe, 14 and I only really made headway in tackling it after a massive crisis forced me to address it a year ago. Even though I'm making progress I'm still not a 'happy' person, I'm just less miserable, I feel devoid of my own ambitions or emotions a lot of the time.

I only really seem to actually 'feel' negative emotions and am not affected by positive things.

I've been dating my gf for going on 4yrs now. We started out long distance and only in the last year have we closed down our distance and for the last 4 months we've been living together.

I get momentary flashes, when I'm in a particularly good mood, that I like her but I wouldn't call it love. And a much larger percentage of the time I'm irritated or not affected by her.

I think we are good together, logically speaking, but I don't think I love her.

But I don't love my own life either, and until a year ago I didn't even want to live my own life so I'm my own worst enemy.

I'm just really confused and I don't know what to do so I thought I'd soundboard off of reddit, seeing as I'm awake and can't sleep anyway.