she's killing me

so , my first year in college and i was 19 years old . First time i liked a girl after breaking up with my first ex , she was really cute and i really loved her smile .I thought it was stupid thought to talk to her untill she sent me an invitation on FB whe she saw my name on the comment section in the university group , we talked the whole night about deep stuff like her best friend wich ignoring her and stuff like that and from that night we were talking always . After a month or two from knowing each other i told her that i want us to be more then friends but she was " oh i don't feel that way about you , but don't worry i will not change arround you after this" we were best friends and i accepted that fact . One day in the summer vacation she told me that she feels and she likes me and i was like " do you remember the day you asked me if her feelings changes what should i do " she said " yes , you'll wait for me coz i'm worth it as you said" but something was wrong , she was not sure 100% of her decision and if she thought more about it she will never say that, .Anyways I thought i had the happy ending but after 15 days i woke up on her text telling me she wants to end it , i thought that will be better for both sides thought she didn't give me the chance to prove how i feel coz of the lack of contact and no hanging outs ... here we are best friends again but this time i was sure of my feelings , just friends and nothing more than that i even introduced her to one of my friends 2 months ago and i was really happy for both of them but it didn't work out , after breaking up with him i felt a different stuff , she was really sweet with me more than the usual day stuff and she never get bored talking to me the whole day . We were talking more than before she even changed her name on my phone to "baby" with hearts and i felt like she was pushing me to tell here 'let's give it another chance'.5 Days ago i told her that i don't think our story ends in the friendship zone and she should knows that , i was surprised by her text telling me that "that's what i think too". To be honest i was really happy coz i thought am in love with her otherwise it can't be a crush for 1 year and a half but she told me to slow down and let her think about it . I was totally ok about that but she shocked me with something really strange after 4 days . We were talking about something and i mentionned a boy as an example ( she liked this boy in high school as she told me and they got back in contact months ago , but he wanted to **** her and nothing more so she ignored him).So this boy called her 2 days ago asking her out for a coffe,she told him that she will call him as soon as she get free because of many courses.Guys please help me ASAP what should i do i can't think anymore
Thank you for reading and sorry for the bad english