pre-flop you aren't doing too much wrong. You should try to defend your bb more (by 3-betting/calling as appropriate - remember their steal ranges are as weak as yours = don't be calling 22-88 much), fold to 3-bets a little less often, and 3b the button some more (i'm guessing). But pre-flop isn't where you're running into huge problems.

Some thoughts
1) your leaks are mostly post-flop i'm guessing
2) you have position most of the time, but fail to use it
3) you forget to pot control sometimes
4) you forget to value bet multiple streets

re-read everything you've read about c-betting, reconsider the lines you can play with sets, reconsider how you play top pair/overpair type of hands. Post the 5 biggest losing and biggest winning hands from the last 1k hands in this thread (without results, but with reads)