What should i do? Should i stay and see, or leave?

So iv been with this girl for awhile now, were "dating" but not "official", which worries me becuz idk if she would do anything with another guy or not since were not "official", we kiss an have done more, we hangout practically everyday, she flirtatious, an shes just friends with other guys an that worries me too, iv come to relize that i have very strong feelings for the girl, she tells me she cares about me an such, but idk if the feeling is mutually, she says shes not ready too be in a relationship, even though weve dated before, so whatever that means, an i always wonder if shes going to break it off an go for another guy. Some people tell me to let her go if shes going to be this difficult, an that shes leading me on an im going to get hurt, iv been thinking alot about it an im not sure what to do, it kills me to think about this becuz i think there can be something... I told her that if she doesnt want to date me, (which i have been giving her time to think about an i dont pressure her at all) that i cant be just friends becuz i like here way too much an i dont want to go through the exact samething the last time we dated... HELP!!!!!