Blind stealing won't help enough.

The problem is that you're not used to playing weak hands. Particularly in the spots where they perform best. In position against weak opponents who figure to have as bad or worse of a hand.

6 max penny stakes is the best cure I know of for this.

I suspect that when you experiemented with LAgg you played micros and just blindly tried to blow people off hands. That's not what opening your ranges is all about. It's about getting your strong stuff paid, controling the pot size and finding thinner value bets.