<human>: So I think me and my girlfriend of four years just split up. It was mutual but I don't know how to feel about it.

 It was my fault I made bad decisions and acted selfishly most of the time which had lead to a very unhealthy relationship for both of us. I feel like I've just lost the most beautiful thing in the world but I want her to be happy. 

I've always been a selfish person and this is honestly the first not-selfish thing I've ever done but it honestly feels like I just lost a massive part of myself just now.. Does anyone have any experience in this?

Give me a shortened version of the text
<bot>: I fucked up so bad early in a long term relationship that it became unbearable for both us in the end. How do I deal with this?