Jumping to the point right away...
Last 2-3 weeks, girlfriend turned me down sexually for all the three occasions. First time subtly, and the second because we had only 20 minutes. And now two days ago, we did some other things, so foreplay came last. There was some messing around with clothes on. But at another point, we were both turned on and half undressed, and made out real slowly, even talked in the middle (mistake) - so I escalated again to the point of fingering, which furthermore showed as a green light to take her pants off. Then she suddenly stopped responding to anything. I then had to ask if she's not in the mood, and the answer was "no". With her being really uncomfortable and "sorry". So she starts explaining what is it all about. How she prefers it slow, without worrying that clock alarm could ring every minute if we get into it. Again, the running out of time is really justified reason in these few cases. I told her to not make big deal out of it, however I can't help but feel rejected, despite her communicating it well and worried that I may start to think "the problem is me".
Also, she had some drinking events related to graduating these weeks. I have bad experiences with girls drinking. That put aside, during that talk which delayed our foreplay, she told me how she's been hitted on in a creepy way in a bar in front of her friends, and even a bit disturbed, so it came out it would be no problem if I confront this guy should he continue stalking. And she was suspicious about intentions of another guy, thus asked me how to react about his request on social network.
Now, isolated part of today's chat:
Her: [mentions something sexual but really shortly]
Me: [checking if she's turned on]
Her: Mm..

Me: I'm horny since.. [here I mention something with her from 2 days ago]
Her: That's a long time
Me: Correct
Her:

Her: [tells she goes to study]
Me: good luck
Her: [something random]
(I make a pause)
Her: [gives me a good night line]
(
here I ignore completely and don't return anything) - which is first time I did something like that. Do you think this is appropriate?
Text is hard to analyse, but because we haven't had sex a while, "That's a long time" line with a wink sounds misplaced, like its me having needs and she mocks me, + she now doesn't give me hints that we'll make it up anymore.
So I refuse to answer to her "emotional" side of relationship because I feel frustrated sexually. I can't control it, and had to ignore her. Do you think I overreact or should proceed with a soft next?
I can't accuse her of cheating, or such things out of the blue, it could cause problems where there are none.