You seem to have a lot of problems with Doomfist.
I don’t, and here’s why:
Whenever an enemy Doomfist appears- he’s either going to be going after your backline or abusing your tanks. If you’re playing DPS, your job is to peel and protect the heroes that would otherwise be at a loss for doing so.
If you’re a tank like Reinhardt Zarya or Winston- it’s better to switch to heroes that don’t immediately get stomped by Doomfist due to lack of utility. Keep in mind Orisa and Roadhog would fit perfectly for Doomfist- and Wrecking Ball’s consistent pestering can force the ‘backliner’ DF to peel back for his team.
If you’re a Support, it’s better to swap out for supports that don’t have to deal with DF, or just have an easier time doing so. Moira, Lucio, Mercy, and (if you’re good at timing- which I am, which is why I use her) Brigitte. Baptiste can be good on certain maps- but he’s not as recommended. Anything that can help you peel or stay alive long enough to keep synergy with your team in order to deal with him.
The reason I didn’t list the DPS here is because most DPS can deal with him effectively- aside from Sym or Soldier. All that matters is how you position yourself and how well you and your team can focus fire.
Doomfist doesn’t need a nerf. The player was just really good, and you lost to that. Try counterplay, communicate with your team (aaand depending on rank- it may seem harder, but grouping always helps me- so it can do that for you too), and learn what hard counters him with minimal effort. Sombra actually requires a bit more effort to be placed into a team with a lack of coordination- so I recommend utilizing Ashe or Mccree. High Burst + CC / Mobility when used properly can both peel your team, and save yourself.
I tend to do this more often than naught with Tracers. It’s fun.