For me, my first weakness is
bankroll management i'm not respecting the rules for both cash games and mtts, i like taking risks, sometimes it pays and when not... i'm broke.
My second weakness is not folding to 3bet with small and medium pocket pairs, i know that it's -EV but i'm getting obsessed with those players who 3bet with T9s 56s but sometimes V is 3betting with premium hands and i'm not folding especially when the flop is T high or less.
And finally my WTSD is pretty high, i have to do more folds on the river.