Dan, thats exactly the same situation I was in...... I lost a girlfriend, my best friend and the woman that I thought I was going to be with for the rest of my life, have kids the works......and I'm so bloody fussy that that was the thing that was worst for me.
What you have said about checking texts every day is a sign of how it would be if you kept in contact, especially every day...... it will eat away at you and you will not be able to move on.
Don't get me wrong, its definitely not going to easy not to contact her as there will be times when you feel really low and lonely etc. But thats more the reason why you need to find something new that YOU want to do, to keep yourself occupied etc and trust me, no matter that its a big cliche, but in time it will get easier!!
There is nothing to say that in the future that you will not be able to decide that you do want to stay in touch, its just that for now, its not the best thing for you to do!
Keep your chin up mate, try not to dwell and beat yourself up...... it took me a long, long time but I finally realised that I did nothing wrong, everything right and at the end of the day then if she couldn't see the value in what we had, and that she wasn't going to get everything she had with me everyday....... then it was her loss and she WILL regret it someday. That's not arrogance, its just self worth, took me ages to get to that stage....... and you will get there as well mate.
Its also good to see that people are not scared about talking about feelings on here. Who'd have thought that behind all that bravado and crap post whoring that theres a group of sensitve souls here
Anyway Dan I know it seems like you on your own, but we're here for you mate!