Hey 897,
Man your graph there for the month reminded me of mine for 1/2. I had to take a break which seems to have helped, and also given me a new outlook.
Your problem may be different then mine since mine was that I was playing for quantity, but trust me there is probubly something subconciously holding you back from allowing you to make big profits and keep them. I know for me everytime i made big profits I went straight to the graphs to see how good I was doing and then expected it to continue, subconciously loosening up my game expecting to win with weaker holdings.
As for the table selector, I do not use it anymore. I tried it but found I could select my own tables better.
What I look for at tables to sit down is an average pot of 4.5 BBs or more and more than 22% players per flop. I then join all waiting lists and take the first ones that come. I will play at the table if there is 1-3 players with VPIPs of over 30. I dont usually care about the PFR but if the VPIP is high then a high PFR is great. If there is 4 or more people with 30 VPIP or more then I'll play at the table to get a feel. If its so random that good play is consistantly not rewarded I will usually leave.
As for the nits, I rarely worry about them. If you come up against them you just tighten up your calling and reraising range. The real profit to be made from nits is on dry boards. A dry board produces a ripe opportunity to reraise a nit on the flop and steal away a pot. If you get 3 bet you are probubly up against a big pocket pair or trips, but most nits do not have the mental compacity to rebluff back at you. 50% of them will call and check/fold on the turn to another dry card and the other 50% will just fold to the reraise on the flop. Remember, if they play back on the flop or turn you better be holding near nuts or else you are going to lose.
One thing I have noticed for you was something that I recently noticed for myself. When we play strong hands preflop and on the flop we expect to win and we think we deserve to win. When we get outdrawn on the turn or river we take it personally. I realized that if I played the hand right I shouldn't be mad or frusterated. We chose a game that is based of uncontrolable outcomes. We need to remember this everytime we lose a hand.
Another thing is that for me at least, I realized my flop and turn game wasn't strong enough and have worked diligently to study where I am going wrong. I realized that I am not killing odds on draws enough. I'm not utilizing other players betting iniciative on the flop enough by way of reraises to get drawing hands to fold. My W$SD wasn't high enough, and my personal belief is that it should be over 50%. Of course at times you will have bad luck and it wont, but sometimes you just have to cut your loses and not go to the showdown.
I hope this rather long post re inspires you to make another stab at poker. If all else fails come to Pokerstars where the games are plentiful.