scared to loose him

I've started seeing this guy and he is so lovley and kind and funny and he treats me so nicely that I'm scared to loose him. I spend so much time worrying I'll loose him or he'll stop liking me because I can't work out how someone so perfect wants someone as avarage as me. It's really weird I've never liked someone to the point I'm scared of loosing them and I don't know if I like that feeling