I have a buddy who just started playing 2NL on Carbon poker
and I hear the same things from him a lot. Usually its just 1 or 2 hands a session that he makes a big mistake with, but really if you just play tight and bet your hands hard when you hit you should do alright over 10,000 hands. Try value betting more when you hit and less when you don't If you are watching videos and reading about 200NL you are missing value from uNL players.
You can do a lot of things that you couldn't at higher stakes, esp bodog! bet 1/2 pot when you miss the flop and bet pot when you hit, making exploitable plays like this will make a huge difference in your showdown and non-showdown winnings... Just my 2c though