Help by newbie really wanted!!

I just read a post of a newbie who "only" won 560 $ with his first 40.000 hands. This was absolutely frustrating for me!! In the moment I am at 30.000 hands and I lost 400 $. The issue is not the loss, the real issue is that things seem to get worse every day!
When I started playing poker in May 2005 I first read "Winning low limt poker" by Lee Jones and "52 Tips ..." by Barry Shulman, before reading TOP by D.Sklansky and "Internet Texas Holdem" by Matthew Hilger. I was playing roughly even for two months. But then it became worse every month. Reading more seemed not to help. In November I am at - 5$/100 BB, which is the worst result ever. I only play 0,5/1 $ in 10 player tables on CoralEuroBet and Carribean Sun.
What I do not understand is that my stats seem to be alright. 23% preflop rate (saw flops all hands), 56% wins at show down went to SD 31%), W$WSF is 33%. My aggression factor is below 0,71 (preflop 0,30), but I am working on it. My question is, what should I do to improve? I really want to understand what the issue is? One seems to be that I often loose expensive hands. The last example was nuts FH to quads (2 sixes in the hole). But is there some other fundamental mistake that I make?? Or how do I find out what is wrong?? Thanks for your support in this issue.