<human>: Hi everyone,

I dated a girl for four years and we lived together for the last two years. We were madly in love and seriously was the best time of my life. However, I fell into depression during the end of our relationship due to work and life stress. I lost my sex drive and stopped 'trying' in our relationship. I stopped nurturing a relationship like it needs to be and stopped giving effort into making her happy. She wanted me to see a therapist about my problems, but I never had the will to go through with it.

We then broke up and she started seeing someone else. It's been four months and I'm now moved out, but still haunted by this everyday, and probably will be for a long time.

I have this massive amount of guilt about losing her and letting our relationship crumble. The guilt is what kills me. I keep thinking that if I would have just tried a bit harder, I could have just kept the relationship which we worked so hard on and kept the girl I loved happy. I feel this is the biggest failure of my life and it's hard to pick myself back up from.

I talk to some friends about it and they say I'll find someone better for me, which I know I will eventually, but I know they probably agree that I stopped trying too. 

How do I learn to accept the guilt and move on? Has anyone been in a similar situation?

Thanks everyone, in advance.

Can you condense the text into a few key points?
<bot>: GF broke up with me after 4 years, because I stopped trying in our relationship. Need help getting over the guilt of losing such a great person.