If you look at the datasheet for the 12f1822 you will see that only pins A.0, A.1, A.2 and A.4 have cap sense capability.
You will have to work with those pins.

Also, as Charlie and others have pointed out, I would not do the Zener regulator. It is inefficient and does not allow one to draw more or less current as your circuit might demand, at least not efficiently.

The Zener regulator idea was a bad one... especially with the LDO regulators available for about the same cost and parts count.