Initially looking at this graph I wouldn't jump to a conclussion that you are being coolered as your EV matches that of your winnings. This could however be you running in to the top of your opponents ranges in spots where the situation would be exactly the same the other way round.
Finding leaks from this I think is difficult but you can check areas such as:
[*] VPIP by position, you should be opening tighter in EP than you are in the CO and BTN.
[*] How often are you cold calling 3-bets (hands like QKo OOP when flatting can cost a lot)
[*] How often are you c-betting? Is it effective? Check statistics and if you are c-betting >50% thats a good start, check your c-bet success. You may be c-betting boards which smash a EP's opening range and losing money that way.
[*] One thing I see in your graph is a lot of swings in your showdown winnings, are you calling effectively on the river, filter out pots over 100bb that went to showdown and hero lost. Review these and see if you think your calls were too loose.
It is all about having your own ideas about your play, if you think of one thing and analyse it and then use that improvement for your next session your game will improve but you must put the work in. I am no NLH expert by any stretch of the imagination but they are a few suggestions.