Lost my girl, cause I gave too much of a fkcu?

Dated this girl, we started to slowly get closer, she would stay over knowing ahead of time that I wake up early to catch a bus. She would sometimes lay in bed and wait until the last minute to get up. this eventually got annoying and I let it affect my attitude with her sometimes. So we'd catch the bus after rushing but i would kind of be mad with her for some reason. and this would last all the way through when we had breakfast together at the dining hall. We didnt really argue ever and on the weekends i was care free so we had a better time then. She eventually broke it off with me cause she said we were arguing all the time and that, I kept getting weirder and weirder. Im assuming i changed from being my fun self to being the I care too much about the little things you keep doing. She was 19 college freshman and Im 22 college senior. When she originally ended our relationship she said things were getting too serious and that she needed to concentrate on school. (And it also didnt help that when i couldnt see her for a week cause she had pink eye we ran into each other on campus and she asked if i was inviting her over but i had a midterm to study for so the next day i asked her to come over and she said she needed to catch up on sleep. This was really shady to me. I was trying to text my friend I think im losing my girl but i accidentally sent it to her, and thats when she said i wasnt ready for a boy.) We texted a little after that I thought she would come back, so we could talk about what was wrong and move forward. She drunk texted me on a sun or mon night saying hey how are you? I found out she was drinking at a frat house. I didnt care when we were together but because she said she didnt want to be with me because of school but she had time to drink at a frat house kind of upset me so i said nice! Glad im not in the way of your studies anymore. her response: are you trying to be rude or does it come naturally (she was always witty like that) she also called me when i didnt respond to it. It was because i was at work. I called her later and she didnt answer cause she was sleep but she texted back asking what was up I said nothing important and that I missed her and she said she missed me to and that was the last normal conversation we had. 3-4wks later she hooked up with some 26yr old town local dining hall employee. She's a 19yr old college freshman, Im sure they were "friends" while she thought we were having problems (she was just taking me too seriously as far as our arguments go) I chilled and left it alone for a while I never contacted her about for at least a month until i saw on his page that they people where saying they where my schools newest love birds and that she loved him. i got pissed and impulsively called her. I stayed calm said a few things asked what was up with her and this dude and i just got angrier and angrier and i ended up yelling saying a bunch of irrational stuff. By the end of the conversation, she said i dont even want to be friends with you anymore and that this dude was perfect, and she kept saying goodbye goodbye. so i just hung up the phone and deleted her from my account. Long story but seems like besides her immaturity and me not knowing how to deal with her or having a relationship. I just gave too much of fkcu!