I think you should stop playing too many tables at once.
Also, keep big pots for big pot hands. For me, that is sets+.
With that, I mean don't threebet with a hand that's not worthy a threebet. One such hand, you're never gonna fold anyway.
I believe this will keep you out of a lot of trouble.

But then again, for now I'm a SnG player until I can get to 100NL, so don't pay too much attention to what I say. I only have some limited experience at 25NL, but for now, I believe SnG's at around the same level are more profitable for me.