jeez...that is one whole long story.

1) I can see you love your gf so much even when you meet your colleague
2) You are not a bad guy, you just confused
3) Your should stop yourself getting attracted by your colleague adn remember you had a good gf already. Nothing could compare to your gf.
4) Ask your gf and you to restart again and promise her you would not think of your colleague again.
5) Every time you go work, just think about work and finish it on time. Work hard and earn money like a freaking busy boss.

patch up d. then good lah.

I clap for your happiness.