NOOOOOO!!
first, on hand 2, just 4bet and get in preflop, yeah.
but let's expand on a few points on bluffing:
- don't try to make overpairs fold in a 3bet pot (specially not AA)
- don't try to rep super narrow ranges (ie, sets only) when you're bluffing
you want to bluff people when you think that they are weak, not when they are strong.
you also don't rep sets very well because being in position you'd probably call and slowplay in position.
in that spot, there is no reason at all as to why you would want to turn KK into a bluff. as you said yourself, there are enough hands that you beat.
it's a pretty dry board so just play it like your entire range and call down.
again, you could just have 4bet preflop.
if you have been running bad recently, that might be getting in the way of your game.