This is the reading materials section so I'll address that.
You have discovered that you could be doing some things better. Congratulations, this is like the 12 step program, admitting you have a problem is step one.
Are you only playing tournaments? If you are playing cash games, there are other choices of the same types of books to pick from.
step one: admit you have a problem - check
step two: buy a math book (Poker Math that Matters (cash) or the math of hold'em (this one has tournament math but isn't as well written.)
step three: buy a theory book
step four: buy a psychology book
step five: consider buying a bankroll, strategy or hand reading book
step six: read books, apply knowledge
step seven: evolve fish-donk
Or did you want just one book? Then read Phil Gordon's Little Green Book