Ive been playing poker online for years and I play in a local game every week.  I have been a very unsuccesssfuly player online as I have never shown discipline and lost a fortune playing cash games.  When I play live, i tighten up and become a steadier player as Ive set aside specific time to play, but, I still get nervous.  I have had some recent success in winning MTT in the local casino and Ive had a good track record of winning in my local free for all game. But..... i fear that I can not take my game to the next level because I lack discipline.  I play too many marginal hands from the wrong position. 

I have historically been aggressive which yields results, however, I have translated these few results into thinking that its a standard play to play marginal, K10 off for example in the early position with a heavy raise. Then, think im ahead if i hit top pair with my medium kicker.  I am a weak player but im trying to get better.  I'm trying to fold 55 or 66 out of position but as its no against the grain, its hard to develop this startegy consistantly. 

I reckon if I play less hands, and avoid only premium hands out of position, then i have the rest of the tools to make progress.  Why then, is it so hard to maintain this when i'm being bullied by someone and I see my stack size reduce compared to the constant agressor.