If you want to know what I think...I think you've been together long enough for some pretty serious feelings for each other to take root.
I think she might be in love with you. And for some women, that is not easy for them...possibly due to a lot of extra baggage.
She may be trying to reject the notion of being in love.
It might be bringing up the extra baggage instead of staying shoved in a closet in her mind where she put it.
And the worst thing you could do right now is give her the impression that you "need" her, because she will see that as being "needy".
Getting back in touch with you has to be HER idea.
I'm going through this myself.
Actually, I'm so pissed of at what an ass my girlfriend was towards me, that I'm considering this a break up.
She wants distance...she's got it!!!
There could be other, more nefarious reasons, as I suspect might be the case with my girlfriend (or ex???).
With mine, I suspect another man may have been involved.
And the very suggestion of it got her so pissed off that she needed "space" from me.
But in your case, I don't think so.
I don't know what to tell you.
Normally, I'd say, check in with her once in awhile and be sweet. Just be the safe harbor when her ship comes back that way.
Allow her the space to work out her issues.
Yes, you and her have been close enough to share everything. Issues, even toothbrushes.
But now, YOU have become the issue.
This may be a major turning point for her...where she has to make the decision to invest her entire self in you, or run away like a scared rabbit.
I think I lost my girlfriend.
But I don't want to see you lose yours.
And I know this isn't easy on you because you love her.
But this is the way it is with a lot of women. In fact, there must be something in the water, because I'm seeing this a lot.
Do keep in mind there are a lot of really wonderful women out there. I know you don't want to hear this, but if her issues, extra baggage that was never dealt with, or whatever you want to call it, causes her to require all this "space" from you...the danger is, if you're even still going to be there when she gets over it.
I had a girlfriend back in college do this same exact thing.
She wanted space, and she was gone for TWO MONTHS!
I spent the first month in grief. (We had dated about as long as you two).
By the end of the second month, I decided to pick myself up by my boot straps and move on.
I brought home a new girl...and she found out and raged at my front door in heartbreak!!! I had to have the cops take her home.
Why girls do this, I don't know.
But it's extremely counter-productive to a relationship...and could be one reason they're still single.