Can a guy change his perception of you if you decline sex with him?

This guy I was kinda talking to for 3 weeks just recently asked me if I'd like to be his fwb (friends with benefits). We also had two arguments. The first being that I told him not to mess with my feelings and the other was rumors at school that he had a girlfriend (which he still denies). We're ok now, but I think the sparks aren't as strong anymore. Then he texted me saying that he's not looking for a girlfriend right now and doesn't want to waste my time when he asked me if I'd like to be his fwb. I told him I don't do casual sex and wanted to stay platonic friends with him. I was hoping that we'd get to know each other to where we could have a relationship. Do you think he'll think better of me now that I told him I won't sleep with him casually? We've never been intimate. The only thing we did was give each other a hug when we'd say hello or goodbye. Thanks!