The encouraging thing about what you wrote is your response to your partner telling you how she feels. To me, that is a great sign. If you said you didn't really care or just blamed her for everything, I'd be more worried.

It sounds like you have a whole lot going on right now and quite a bit of pressure, possibly from a couple different sources (one of them being you). I agree with @sarahsweets--it seems like some sort of therapy situation might be helpful. Having been in a couple fairly long-term relationships, I can tell you, if you don't address this, your partner is going to be an unhappy woman. And you don't want that.