My ex (together 3 years) and I have been apart 3 weeks.
But everywhere I go I seem to run into her.

I live 5 minutes away from my ex.
I do my shopping at the same area.
We have passed each other on the roads every second or third day (she'll drive beside me and wave)
We go out to the same places at night.


In 3 weeks, I have seen her (at a distance, no talk) more than when we were together.
I've spoken to her at least three times a week, either in phone calls or bumping into each other.

I'm finding all of this is making my life harder. I don't want to live at home and not do anything, but I don't want to feel like I shouldn't be able to walk down the street without my eyes being peeled to see if she is around, then avoid her.

I'm happy to do NC and get on with my life. But HOW?

I understand the confusion, check out the links in my signature.

Try doing things at different times of the day. Not only will that put you out at different times but a change in your schedule will be new a different and provide your mind with something else to focus on. Go shopping (by shopping I assume you mean at a supermarket) at a new place.