Why do I keep getting cut looking flats?
Is the cut always the same distance around the tube from the valve?

If so then you have something wrong in your rim.  Use the punctured tube to measure where the damage is coming from... that will give you at most two positions, one in front of the valve hole and one behind.

I think you'll find a cause in this very small sector of the rim.

BTW - had you patched your tubes rather than replacing them, the punctures might have been reduced by the extra thickness of the patch in that spot.  And if they punctured again though the patch, then you'd know straight away something's wrong there.