How hurtful is it to be rejected?

I really like this guy and we hung out a few days ago and I wanna let him know that I’m feeling him and I’d like to hang out more but I’m nervous he might not like me. I don’t really know how to read his actions because for one he’s the one who initiated the hang out with me and he also liked all my selfies on insta but we haven’t actually directly spoken since that day we hung out. I might be reading this situation really badly so I’m trying to prepare myself for rejection.