Presuming the light brown line is your EV, based on your comment it's a case of stacking off too light or overplaying in most spots post flop, as suggested post hands and have them evaluated. Don't get creative at 2NL, look for optimal spots to stack off as opposed to barrel 2-3 streets expecting folds, also I think you're getting too FPS pre flop, keep it in your arsenal but don't overuse 3betting light, as mentioned you haven't played enough hands to have sufficient information on your opponents regarding 3bet %'s, carry on with stealing in position.
-Steal often.
-3bet less.
-cbet a ton.
-vbet where appropriate.
-Look at spots where you stacked off light and make a mental note.
-Pot control is super important.
EDIT-- Is this 6max or fullring?
EDIT2-- Apologies, missed your VPIP PFR, 14-11 / 13-11 is good for FR and as mentioned there is too big a gap regarding your vpip/pfr, you can play optimally from EP but I think you should add an extra couple % to your stealing range in LP/MP (but again, don't over do it).