Phildo, it would appear you've hit a plateau. Albeit, its down there, but every player goes through periods of introspection where there game stagnates for a while before jumping (i mean it, it'll go up fast).

The best thing to do, is keep an open mind, read as much FTR as you can, and studying some books is always good (Sklansky is good for theory of poker and Holdem for advanced Players) I myself (at times only myself) am a big fan of Brunson's super system, It's not a bible, but it did help my game tremendously, and if your playing live games a lot, get Caro's Book of Tells, its definately worth it.

You can also pester the Gurus on here, im not gonna inflate their ego's by giving names but you'll see them posting a lot.