I was with my first girlfriend for 4 years and we started living together after we had been dating only 5 or 6 months. I was 19 at the time and she was 20. After about the 3rd year of our relationship we began to start having some problems. We used to work together in the same place but I found a new job with strict 8-5 hours and weekends off which contradicted her swingshift work schedule. So we didn't see each other as often and because we now worked in different places we had different sets of friends. Her carefree, stay up all night and party any day of the week but still go to work the next day lifestyle conflicted with my traditional in bed by 11 up by 7 monday through friday lifestyle. We started fighting all the time over stupid things and sometimes ended up being downright mean to each other. I hated how our relationship was turning out but at the same time i'd been with her for so long that I couldn't imagine breathing without her there beside me. It was torture. On one hand I knew things weren't working out and I didn't want to be with her anymore but on the other deep down I loved her to death and didn't want to give up. So we stuck it out another year and things went from bad to worse. Our relationship totally crumbled and it was devastating to both of us. It got to the point where the two of us couldn't be alone in the apartment with each other at the same time because we fought so bitterly. We had never been violent with each other before but one day she came at me and I was seriously afraid she would hurt me. Shortly after that I gave up and moved out. It was horrible. I carried so much hate for her for so long. It took about a year before I would agree to even be at the same place she was. We met up one night and tried to talk out our issues but while it helped, it didn't solve everything. Maybe a year after that we met again and finally hashed out all our problems from the past and finally said our apologies and became friends again. We aren't close friends but I make sure not too much time goes by without checking up on her and making sure she is ok.

Super long story short - I see myself in the same situation you are in now. And looking back I wish that we had ended things before it got so bad. Its so hard to end a relationship, especially one that you've been in for so long. You've built your life around someone and its so hard to turn your back on it and start over. Ultimately though if I could do it again, I would have said my goodbyes and moved on before we tried to ruin each others lives. No one can tell you what the right thing to do in your particular situation. This is what happened to me and this is what the results were. For you, maybe things will work out, maybe they won't. You have to decide how much you are willing to deal with and ultimately when the right time (if ever) is to say goodbye. Its very hard to determine when the right time is to say goodbye. Its just something you have to decide for yourself.

Good luck in this relationship. Keep in mind that its horrible to go through the ending of a relationship but inevitably life goes on (whether you want it to or not) and you do find happiness again.