I made a big mistake?

I "dipped my pen in comany ink" I "crapped where I eat"... I saw a girl in my national guard unit for about a month. Our first "date" I took her out to an expensive dinner(I know bad idea for a first date), but it actually went quite well and she acted like she was into me. I also took her to a concert and bought the ticket. I didnt call her my girlfriend but I figured that where it was headed. She kissed me alot and we made out alot too. We would snuggle together at my apartment and watch movies. We cooked dinner together as well. she always wanted me to touch her body, she said I had the softest hands.. anyways I was really unsure and I asked her what I was to her and she said we were friends. I told her I had feelings and she said she wasnt looking for a boyfriend, but I know she has been talking to other guys besides me. She said I was moving too fast and a little clingy. I guess i should not have spend all that money on her so early, so I can understand where shes coming from I guess. But now I'll have to see her atleast once a month when we have drill together. Im not going to spite her or anything, but I feel its going to be a little awkward im going to pretend nothing ever happened and just treat her as a fellow soldier/ acquaitance. Any suggestions?? Anyone been in a similar situation with people in the workplace??