You call too many 3bets imo. Your calling about 40% AND 5NL PLAYERS ARENT 3BETTING LIGHT/SEMIBLUFFING VERY OFTEN.
Thats going to leak money.

Thats the only thing I saw in your pre stats but thats big b/c 3bet pots are large to begin with even before the flop comes...
Your postflop skills are prob the issue, you might be calling too many river bets from fish or take med hands too far etc...