She feels uncomfortable around me, can we ever get together?

my sisters bestfriend and i got to know each other really well, and one night we were talking on the phone and i told her i liked her, and we agreed to be fwb. i wanted to be more, and she was willing to make out and do stuff with me, but i got insecure and obsessive and now she feels awkward to be with me. i kept bothering asking if we could ever be together again, but she found a boyfriend. i kept asking and she finally told me we could never be more than friends, i persisted that we could, and now shes not responding to my texts and she doesnt want to see me right now. what should i do? and is it possible with time we could ever be together?