Stats don't tell everything. Just gives you an idea. If you improved recently it's hard to see from the overview due to your stats been lifetime. Kinda wish there was an option to see the last week or month instead of whole lifetime average. From your stats though it seems like you should focus on surviving more as you die a bit often but it's hard to see without watching you play. Reducing your deaths will increase your up time so you can contribute more kills, healing and blocking damage for your team. If you post footage of a typical game it might be easier to pinpoint how to improve.
I feel the best option for me is to get players on GAF to practice with me, to see how they can help me improve.
For Lucio, I always try to stay close to my team in the back line behind them, in order to provide the necessary health buffs, but I will speed boost back to the center for protection If I ever get flanked. If my team gets destroyed and I survive, I'll head back to the spawn room to use Speed Boost+Amp It Up to get them back into the fight.
In Zenyatta's case, I have a bad habit of overextending, which leads me to a quick, painful death. I need to space him out more effectively, so that I won't get squashed or singled out by the opposing team.
Zarya is a weird case, as I know how to time her particle barriers, but I never know when to use her main beam or grenade launcher during her ultimate. Her grenades do more damage, right?
I try to play more aggressively with D.Va, but that tends me to go kaboom more times then I care to admit. Ganking and harassing is her bread and butter, but enemy players seem to know how to telegraph what I do beforehand.
