My gf is pretty mad and wont talk to me help!!?

[A kid]

Recently, my GF has been really pissed at me because i hang out with my friends more than her. I understand that she is mad about it and i know I'm a jerk sometimes and i admitted that to her. So to make it up to her, i took her to her favorite concert and just my luck 2 of my best friends were there. They started to talk to me and stuff and i looked at my gf cept she wassnt there anymore. She is probably pisssed off and she wont talk to me. Any ideas on what to do now? :/