Need some help with this situation?

so there's this girl I like who used to like me and we went out we didn't work because of miscommunication but thats not there anymore. so we broke up, while we wen out we never kissed and she only flirted and messed with me a little. now that I'm trying to flirt with her she tells me not to because she's not attracted to me anymore. but she's got this new guy, they went out but broke up. she kissed him and they messed around a lot like shed sit in his lap dirty flirt with him and say things like "I'll scream your name if you want me" they mess around like that a lot but she doesn't do that with me. how can I cope with this whn I like her so much she says she won't do that with me unless she likes me but she let's him talk to her like that but says she doesn't like him anymore. it hurts and it sucks what do I do?=/