<human>: Give me the gist of the text in a nutshell

I'll try to keep this short and sweet. This isn't a particularly exotic problem, but I'm trying to get impartial advice.

Two months ago, I started an accelerated program at a local college. This program is very demanding (basically equal to taking 8 university level courses simultaneously), and is very important to me. Because 99% of what I am learning will be directly relevant to my future career, I am devoting a great deal of my time to understanding the material and completing all my course work.

The catch, is that I have been dealing with on and off again depression since my relatively traumatic childhood (long story) and the great deal of stress school is causing sort of exacerbates this. In the past I have used medications to control my mood, but for the fast few years (since me and my GF have been together), I have been off meds. 

To cut to the chase, my mood is dropping, school work is piling up, and my girlfriend is getting angry that I am "always in a bad mood" and not able to spend much quality time with her. I don't dispute this...I am extremely stressed and busy and as a result not a whole lot of fun to be around. To add another layer to this, we live together and she is supporting me while I go to school, which makes me feel extra guilty for not being able to devote more time to her. Oh, and the cherry on top is that my libido is dropping like a rock and as a result we only have sex once every three weeks or so.

We nearly broke up today after a big fight about my low mood, but she decided to stay with her parents for a week to think things over. I feel like my mood is spiraling out of control...these fights are making it impossible to concentrate on the ever-growing pile of work I have, Im losing motivation and starting to feel like breaking up will be best for her. I feel like shit for not being able to give her what she needs, but Ive never had to deal with so many competing demands and the stress ia really getting to me.

Any advice?
<bot>: I am stressed, extremely busy and feel my mental health slipping, and my girlfriend is very upset that I cannot give her the positive attention she deserves.