I have a bit of an eating disorder and its caused me to back out of relationships and sex

so I have this guy that I like and he obviously likes me. we have been hanging out the other night and he asked for a kiss( more like make out) and I said no

;( I told him that it was because I have no experience with men (which is true) but it was actually because I didn't want things to go further than kissing because if clothing comes off I dont want him to think of me as gross or fat. I'm actually a very sexual person but I cant go through with relationships or casual because of my body. what's even worse is

I think I ruined my chances with him because he hasn't texted me

what should I do how do I overcome this so I can have relationships and sex