Please, for the love of Turkey, help me!

[SaggyTTs]

I'm miserable. I am certainly no expert in poker (I play small stakes on Party at 2/4 mostly, some 3/6), but after logging about 50,000 hands, I have been a relatively consistent chugger at about 1.87 BB/100. Lately though, the last two-three months, I can't win anymore. In my last 13,000 or so hands, I am down to about -.50/100. I have actually tightened up more than usual to fix it, but nothing helps (15.63 vol put $ in pot, 6.31% preflop raise). I have basically quit playing small pocket pairs unless near the button and several players in. I don't play suited aces in early position. And I NEVER play ACE/RAG unless in the blinds or maybe ATo on the button or one off. I go to showdown about 30%, but my win is only about 57%.

I have all my stats on poker tracker. It's killing me. I have never been in a streak like this. Could this be due to variance? I am playing better cards than anyone at the table, I feel I do a decent job of protecting my hand through betting and check raising to eliminate folks. Can anyone help me. Is there a key stat that I can look at?