Should I feel bad for hooking up with someone that my friend wasn't dating?

New Year's Eve I went to a party and got pretty drunk. At midnight I kissed a guy that was there who I kind of knew. I knew him because we had a few mutual friends and he was "talking" to my friend but she was "talking to" two other guys (three total). She didn't go with me to this party because she was spending new year's with one of the other guys and asked me to stick to a made up story as to why she couldn't come with me. I sent her an apology message and tried to contact her five times over a month and she did eventually call back. She is now dating someone else. She told a few mutual friends about something very personal about me. Should I even feel bad? I feel like I've done everything I can. I think you can't call dibs on three different guys.