Hi mate
Firstly - sorry you're going through this.
Secondly - i've just been reading back your account of things and what stuck out is that this has only been going on a few months? It's seems a bit step for her to be now saying "she's bored". A kick up the arse might be more understandable but now sort of cutting ties so-to-speak re: going out seems very hasty.
Have you tried to speak to her generally about what's going on with her? How is work / friend-life?
Sometimes people get jealous if they see their friends zipping off to Oz or the USA for 3 weeks without a care in the world. I've been there in my younger years - a lass I was in a serious relationship wanted to go and do everything young people do. I was a stupid without a pot to urinate in. The compromise we made was her going and doing that stuff alone. We ended up forming a stronger relationship because I accepted that she had different views on travelling etc. Whilst we did end up breaking up, it was completely unrelated.
I guess the point i'm making is, perhaps she just wants a bit more independence, a bit more freedom. And whilst that evokes strong emotion that she may leave, you can be in a relationship and have that freedom.
Sounds like it would be great for you both?