I main junkrat because my aiming ability isn’t great for some reason, and it has always been like that. I can still get platinum because my other skills make up for my poor aim.
Playing a hitscan hero is really difficult for me.
My question is, many times junkrat is taken, and I have to pick another hero. All of the other heroes are hitscan. I usually use Torb as the best 2nd alternative. So what other DPS hero do you think I should consider to play when Junkrat is taken?
reaper or pharah maybe…. some might even say hanzo 
I second reaper as long as you know how to position accordingly to the other team. As a preference I take Mei or Sym as the fire from them is rather broad giving an easier time hitting opponents.
I can vouch as a hanzo main. my hanzo accuracy average is higher than my ashe 
Torb.
Flying Junkrat
Reaper
Genji
Sym maybe if your tracking is okay, but if not then mei is good too
I also main junk and torb on dps. I’m probably better with torb but junk is more fun. So my aim probably sucks too. I would pick reaper as my 3rd choice because I like to cheese. ow2 Bastion also seems good but I haven’t really tried playing it, only against. I can sometimes pop off on other dps but not consistently enough.
Reaper is prob the 2nd easiest dps hero to aim with
any particular reason why your aim is bad? i thought i had really bad aim until i reduced my sensitivity A LOT then all of a sudden i could track players, aim better at range, etc.
Pharah is the best alternate hero. But maybe try to improve your aim. What is your mouse dpi and in game sensetivity? What framerate is your game running at? And what is your monitor refresh rate? Getting those setting right can greatly improve your aim.
In OW1 when I felt like being half afk but still climbing the ladder I just learned how to play Torb. Learn all the awkward turret spots, learn where to be spamming your shots, learn when to use your ult to turn a fight around. Went from like 3050 (Low Diamond) to 3800 (Mid Masters), where I turned into flexmeister and climbed all the way to top6 dps EU
Why did no one mention Mei? 
Phara or genji.
They just aim in the rough direction.
Its more about positioning & timing of abilities than pinpoint aim
Mei freeze is good if you cant aim, use it to support your tank to do more damage by slowing the enemies down. Its actually underrated how much freeze-slow down is for increasing your team’s damage output. You can slow and enemy down just enough to icle them.
While Mei is a DPS, you dont always necessarily need to have high damage output, she is great for stall. I think of her as your tank’s pocket support, ice wall when your tank’s shield is down and they need breathing room for healing.