my lesson learned

hey guys.. im kinda jumping in right here this is my first post, i have been dating this girl for 2 years and recently she dumped me. she found out that on 2 occasions i was kissed by 2 different girls. neither of them were really my fault but i admit that i should have turned my head. i broke contact with both girls right after but i was so scared that sarah, my girlfriend, would leave me i kept it to myself and soon forgot about it seeing as the second time i was at a friends house and we were all very very drunk, i had the sence to get up and leave after it happened. well during a break she found out and asked me about it and i told her,.. she then hung up and texted me i have no feelings for you it will be a long time before i can see u again,.. this was 2 days ago. im a complete wreak, iv had so many realizations. she was my first love. i just want one chance because so much would be different. i just cant deal with a life without her. everyone tells me to get over it.. but is there anything i can do.. i just want that one chance, i freakin suck i know but i will never make this mistake again. no more secrets ever again.. shes the only girl i ever loved and we had a lot of firsts together.. help me please