sex with a shirt on.

So I'm 21 and only just had sex for the first time like 3 months ago. Me and the guy who took my virginity only did it a handful of times and always with my shirt on. Like we were both too lazy to take it off I guess. But now like I want to have sex and explore  the sexual world but I feel too insecure to try with anyone else cause I'm kinda like scared ..? to have my shirt taken off because I'm so insecure about my body. I don't want to go have sex and then like stop the guy from trying to take my shirt off so yeah I'm at a loss on how to approach this situation.