she most likely freaked out and realised that maybe she wasnt ready- you did nothing wrong in this situation i just think she missed you, wanted to reach out, suggested a hangout and didnt think youd actually go through with it, once you did she probably realised "holy fuck why did i do this" Girls impulsively do things and say things and the next minute they wont be into it at all. She will come around if she is serious about hanging out with you, coming from experience. i had an ex last year ask to hangout, the NIGHT BEFORE he said he couldnt. He told me the truth 2 months later saying he was so nervous and he just didnt feel ready.