My girlfriend is upset with me... help please!?

well last night my girlfriend called me up askin if i wanted to do kareoke with a few of her friends/Coworkers.. most the night i was sittin by myself while one friend was with her boyfriend and my girlfriend was with another female coworker jus a few feet away.. i got a lil upset cus she wasnt really spending time with me.. shed come over for a few mins and than gravitate over to the over girl.. so i told my girlfriend how i felt and tat i was gnna go home.. my girlfriend gets all pissed at me and is isnt talkin to me.. and wants me to go home.. was it wrong of me to feel secluded? im supposed to talk to her ina bit, what can do or say to make things bettr on the right track? ilove this girl with every bit of me.. i dont want anything to break us up..