What do i do about my girlfriend?

well i had cheated on my gf and i got caught...she went on vacation on the whole month of december...i was talking to her friend on myspace and i guess in a way i was flirting with the girl...but then the same girl i was flirting with and her bestfriend told my gf that i liked that girl and that i was having ual relations with her...so my girlfriend got mad and went with another guy in mexico she tell me she was holding hand and hugging the other guy...luckily she didnt kiss him..but the guy tried to give my girlfriend a hickey on top of her ...so really right now im confused when i cheated on my gf the other girl kissed me and it was only a peck...and i want really flirting with her friend how should i feel and how should i cope with this...i need help fast!