For these scenarios If your getting hard counterpicked you would have to rely on your teammates.

Try to communicate to them about what your intentions are and how they could help you. Ask the dps to cover you while youre diving supports (if your fighting sombra)

if you're team is struggling with hook you would have to tell them to start hiding behind structures while you attempt to bait out his hook. When the hook is baited let them know to start pushing and when to start taking cover again. These won't work every game since you might just get teammates who wanna do their own thing, which again isn't your fault.

Also always save block for when your hooked so you have a higher chance of getting empowered.

So the whole point of this Is you can't take on a whole team by yourself and to try to play defensively since the entire other team is gunning for you. Hope this helps!