<human>: Give me a shortened version of the text

I [18M] can't really turn to anyone I know with this because I don't know how they will react, that is why I am here.

On a school trip to Brussels we spent a few days away from school, and that meant a few days away from my girlfriend [18F]. Before the trip I was very much in the groove of the relationship, feeling loved up every day, we are even going to Italy together in the summer, however after I went to Brussels I have been different. To be more precise something has changed me, to really clarify I'll give some background.

For a long time I've wanted to visit the war graves in Ypres and it's surrounding area, and whilst there I was walking with a girl [17F](we'll call her Holly), and I just felt like I was gelling with her a lot more than anyone else on the trip. In the past we've not really spoken extensively, but that changed these last few days. We danced and laughed and smoke and drank together, all the typical free youth things, and then she was with me for the overwhelming atmosphere of the war graves.

Since spending so much time with her I am at a real conflict in my head, I can't get these new feelings out, I have a girlfriend but I think I'm crushing hard and it just gets worse. I've been having cold sweats and have been feeling sick because I doubt my ability to be a good and loyal boyfriend anymore. I need to get these feelings to go, whilst I'm happy around her, I am ashamed all the rest of the time, I can't talk to my girlfriend properly because all I want to say is that I am no longer fit to be with her. I need her out of my head and need some advice to do so.
<bot>: OP went to Brussels and starting falling for someone other than girlfriend and wants to get back to how things were before my relationship falls apart around them