I too started experiencing cramping and some dizziness after switching to Paleo/Primal. Figured my hydration was the issue and began drinking more water on and off the bike...........
Rolf Devinci Cycling: Salt of the Earth - Rethinking Sodium and Hydration.
You may be getting enough salt from the 20% non primal diet(?) and or cytomax(I avoid sport drinks) but cycling in the heat will cause you to lose lots of electrolytes through sweat. Factor in your self admitted lack of bike fitness and lots of hills it is no wonder the legs were getting cranky.
Hydrate, hydrate and hydrate.......that will be my mantra for an upcoming one day stage race to keep the cramping at bay....i hope. Good luck and ride safe!