Why do I hurt the one I love?

I'm 24 years old and never had a girlfriend that lasted past 6 months. I had a blast being single for the past 6 years. But I met this girl that moved me more than anybody else has ever done. We started dating in May of this year and the more we hung out the more I liked her. We have been together for 8 months, and they have been the greatest 8 months of my life. But 2 months into our relationship I briefly kissed another girl, one of my good friends. I actually proceeded to talk to the girl for a half hour about how I really feel in love with my girlfriend after we stopped. The guilt was overbearing, but I was too afraid to say anything to my girlfriend about it. 2 months in...what if she dumped me then and there? I would never have had the last 6 months be so wonderful. Also, I would text and flirt with girls frequently. Leading them on, and then chickening out if an opportunity ever arose to follow through. Each time I would scold myself and stop and question who I really was, hating myself but always going back another time. My girlfriend found out about the kiss, and I confessed to the texts. There was a rumor a few months ago that I had sex with a girl, but the person who made up the lie confessed to just being angry with me over something and trying to get me back. I told my girlfriend, looked her right in the eye, and said I never have done anything to any girl ever in our relationship. I lied. Broke her trust. She is absolutely crushed and doesn't want to see or talk to me. Says I need to figure out if I want her or want to live the single life I had.... My girlfriend and I are very honest with each other about EVERYTHING. This is the only instance where I have not been faithful. I know there is no excuse ("it was just 1 time"), but I just wish there was a way to convey my feelings to her that I do love her. I am here to ask anyone for assistance on how I can solve this problem I have where I keep thinking of girls and talking to them, then turn around and hug my girlfriend and be the happiest I've ever been. I know I should just man up but it's not like I haven't tried that already. I would do anything to get my girlfriend back and prove to her I am loyal.

if you are looking at, flirting with, texting, and kissing other girls... or even wondering about being with other girls.... you are simply not ready for a long-term committed relationship. As much as you say you love this girl, let her find someone who is committed to her, and let her be happy. Stop stringing her along.

im only 17 years old and ive been in a relationship with the most amazing boy for over a year and a half now. i think what you need to do is get your priorities straight, for me i would never do anything to hurt him, break our trust and ESP not cheat on him, you are a 24 year old man its time to do some growing up, if you really loved your girlfriend that kiss wouldnt have happened. people have NO respect for cheaters and im not trying to be mean by saying this but if you think constantly flirting and talking to other girls is ok then maybe you should just live the single life. because i dont know any girl that would want to share their boyfriend with 10 other girls that he flirts with. im just saying.