<human>: Condense the text into a few key points

We were friends for a couple of years before we started dating, and dated for a year before we got a place together. I wouldn't have moved in with her if I wasn't serious and committed, but after a year of living together, our relationship is nothing like what I expected it to be, and I'm starting to feel down on the whole thing.

I want to be supportive. I know that she's sensitive, and I believe she has self-esteem issues. It feels like every other thing she says to me is a complaint about someone who's slighted or disrespected her, or just a random negative comment about someone or something she doesn't like, and it brings me down.

I've learned that she's not asking me to solve her problems, and I try not to tell her what to do, or what I would do. I used to make mean-spirited jokes about whoever she happened to be complaining about, but I don't feel like that's the person I am, and I don't like doing it. Now I feel like all I can say is, "that sucks," or "how inconsiderate," and I'm starting to feel like a broken record.
<bot>: My girlfriend complains all the time, and it stresses me out and makes me have doubts about our future. What should I do?