stay friends/ or date?

I'm a Junior in High School and my best guy friend is Jarrod, i like him (like really like him... he's told me that he likes me too... we've never messed around or anything, we just hangout) but we always fight- about the stupidist little things (it's a jealousy thing really, i hate when he talks to other girls and he doesn't like being ignored when i'm around other friends) it's obvious around campus that we like eachother, but niether one of us is serious enough to be committed! BUT i want to be in a relationship, but how do u tell someone who may get scared and run off? it's hard. i need help. what do i DO!?