<human>: Can you give me a shortened version of the text?

I (25 M) met a girl (24) online, we've been seeing each other for about a month and texting a lot for a few weeks longer. I last saw her at the weekend, asked her to be my GF in some SAP way, she said yes. I stayed the night Saturday, next morning we had sex for the first time, it was all right, she came so couldn't have been too bad for her either... Cue her having to rush to get ready to go see her friend who'd recently split from her BF, she asks me to leave before the friend arrives which I do.

Before that weekend we were texting a lot, around 100 texts a day. Since Sunday its 1-5 texts a day, she is making no effort, She says it is just because she is busy but its not like her entire life suddenly changed. Did she go off me? I thought we were mutually very into each other.

I'm looking for other peoples opinions, I have no idea what she might be really thinking, I just don't buy the too busy excuse (she's visibly been on FB rather than talking/texting me). my (f) housemate suggested maybe her friends have told her she should be making me chase her.

I've basically switched into self preservation mode, getting annoyed at her lack of communication feels easier than risking her stamping all over my stupidly loved up unprepared heart. 

Other things that might be relevant, she has been single a few years (perhaps not used to dumping guys?), I'm the second guy she's had sex with (this fact alone is the only thing that gives me hope she must have been into me before!)
<bot>: We became girlfriend and boyfriend at the weekend, she now doesn't seem interested, the more I think about it I feel I'm going to get dumped as soon as she admits she's not that into me.