Have you considered building bigger pots earlier in the hand by:
1. 3betting more ip
2. Cbetting the flop bigger, and overbetting (say 1.5 x PSB) the flop some.
3. Ditching TPTK when you get raised on the flop or bet into on the turn.
4. NOT cbetting air so much.
Just curious. Good luck beating 5nl. I know it's really tough these days.