Thank you all for the input and great advice.
Just to clarify some things, what I meant is that my submission is more prevalent in the bedroom (or kitchen, or garden hehe), as opposed to in certain other areas of our relationship. I.e. we make other 'vanilla' decisions with regards to our relationship together as equals, not as a dominant and a submissive.
It's not however just about sex (although that is where I'm having the most problems I think), but with the emotional side of submission also. It all goes hand in hand though. Basically I just can't get in the mood.
I'm sure us being apart is the key factor, although there's no jealousy etc. involved (we were separated due to career stuff on both our parts), I think if anything I spent to much time *not* being as submissive as I normally am and dealing with other things it's as if I've forgotten how.
I'm absolutely sure, at the now ripe old age of 23, that I'm submissive. I have no dominant tendencies in my personal life and am very happy with our relationship as a whole. I know that I can and will get back to that sub place, right now I just don't quite know how.