I feel GUILTY!!! D=

So here's the deal:

I had this guy friend last year and we used to joke around and everything hug each other and just a whole bunch of best friend stuff, but no feelings were involved. Then came the end of the school year and I was at the back of the classroom with him just talking about regular stuff when he tried to KISS ME! I rejected him, saying we were just friends and during the whole summer I thought about him and how things could have gone differently during that moment then when I came back to school this year I saw him again and...instantly fell in love with him (love at first sight I guess). But we have no classes together and it's just miserable without him to cheer me up and make me laugh at mean teachers. So he asked a girl out about 2 weeks ago and I was heartbroken and all but this girl was known to switch to guy to guy and just today he went up to me in the hallway and yelled: "OH MY GOD, SYDNEY! I HAVEN'T SEEN YOU IN FOREVER!!!" and hugged me and kissed me on the cheek! After I looked around guilty and saw that his girlfriend was watching us!!! I feel so guilty and my friend just texted me that they broke up...how do I fix this? I feel guilty...=(