How can I stop feeling weird about this?

a coworker and i were emailing each other and he said let's make luv and i said i wasn't sure. anyway later on in the day, he told me he wanted to touch me and me touch him. i then changed my mind and told him i wanted us to touch. after his shift was over, we met at the top floor of the library which is where we work and we tried find a spot, but he had bad breath and looked unclean. he could tell i wasn't sure and told me we shouldn't do it since i wasn't sure and that i wasn't into it. he just seemed really cool about it when i asked him if he was upset and he seemed laid back. he could tell i was nervous and confused and he kinda hugged me. the next day i emailed him from home saying that I want him and me to still do it, but then he said he couldn't do it since he was horny and that i should do it with some1 i luv since he has a gf . he said he was sorry/ that he hoped i didn't feel used. thing is i try to talk 2 him like nothing happened, but i still feel weird.