I think moving away by yourself is such a courageous thing to do, and I think the thoughts you are having are completely normal and OK.
I think Lisa had some great points. Some time apart (from being a couple, not just distance-wise) is definitely in order. I think looking back, you will be glad you did it. These thoughts you're having are your head/heart telling you something is not right, at least not now. Listen to them. Good luck, sweetie.
__________________
"We live in an age where unnecessary things are our only necessities." --Oscar Wilde
"i tell you one lesson I learned
If you want to be something in life, You ain't gonna get it unless, You give a little bit of sacrifice, Oohh, sometimes before you smile you got to cry.." -The Roots
OMG I think I know exactly how are you feeling!! I have been with my boyfriend for 4 years as of October 5th and I know it's not right. I have only just begun to REALLY feel this way and it's because I am finally gettingout and doing stuff that I want to do. I think no matter how hard it may be you need to go with your gut instinct. Marriage is permanent and I'm sure you don't want to go through a divorce later because you didn't follow a gut feeling now. It will be hard, like I know it will be for me, but in the end, I think you will be happy you made your decision.