What is a good deviation on ,day when trying to quit diet pop?!

Water.
Tea for the caffeine.

Pop is just sugar water with added artificial flavoring..

try drinking pellegrino, or evian. If you like that, you can add flavourings, crystal light or lemon juice and honey or orange cordial.
I am in love with diet soda, so I drink fizzy water with flavour.

But if it's diet, you are drinking calories, I don't get it...

Try more water.