Confused and on edge

Hi All

I need some advice on issues in my relationship with my gf, basically we spent last week together on holiday and whilst away we had intercourse multiple times and the last few times she was the one to initiate it, and she kept saying she couldn't get enough of me.

But now for some reason only a few days on she has become on edge and making it hard for me to make any basic affection, when I asked her what was going on she said "she was afraid I was going to try and jump her, so is trying to keep her distance".

We have been together for over 18 months now so we are well established, but like any couple we have had a few misunderstandings which we are always able to resolve via talking it out.

But this latest episode is making me feel really on edge, confused and struggling to understand what is going on. I am supposed to be going around her place soon, but I am feeling really nervous, even more nervous than when we started dating and feeling like I should not go.

Any advice?

Thanks