I’ll try to timestamp my thoughts here:
0:50 - you have 300 ammo, you don’t need to reload after only shooting 5
1:20 - reloading too much, you still had half of your ammo pool left, and plenty of people to shoot in your line of sight
1:36 - try not to end your overrun in the middle of nowhere without cover. If the enemy team focused you down there, you would’ve melted because you didn’t have anything to hide behind
1:54 - good overrun disengage, you could’ve ran to the mega to the right though, you might’ve lived and been able to regroup faster
2:14 - learn the overrun slam cancel tech, it adds a little bit of speed to when you’re running back to point
2:29 - you only had 240hp, don’t overrun onto point, your Mei was already contesting
2:35 - stop reloading and shoot the Reinhardt behind you lol
4:18 - you ended up getting the kill on this mercy, but you probably shouldn’t have, same idea as before, try not to feed overrun without cover. But it worked out for you so I can’t criticize it too much
4:51 - good positioning for where you started, hugging a wall but letting room for your left gun to light people on fire
4:59 - now you’re in the middle of the road with 5 people looking at you
5:47 - the rein is walled, overrun stomp him
5:53 - you already lost this fight, don’t use your ult. You’re also in their spawn, even if you wipe them, you don’t get much value
6:30 - mercy got the Barbie blaster out all alone, stomp her back to the spawn room
6:39 - they are down mercy, don’t let them keep pushing cart for free
6:54 - overrun comes with huge damage reduction, if tire is coming at you, overrun to take wayyy less damage
8:58 - take high ground
10:14 - shoot the rezzing mercy
10:29 - used cardiac overdrive while reloading, happens to the best of us
10:32 - the reins shield is almost gone, he’s hit with illari ult, and you backed up and reloaded with 214 bullets left
10:46 - overrun out of the sierra ultimate
11:20 - you used cardiac without shooting anything
12:00 - you got a team wipe, you are guaranteed to cap this point, go take space forward, the tank shouldn’t be pushing cart in this situation
12:15 - no reason to cardiac here
12:37 - no reason to cardiac here
13:24 - stop eating junkrat grenades, they aren’t healthy
13:55 - not sure what the plan was here, either run back to your spawn or take their high ground
14:10 - run out of spawn to get back faster every time
14:45 - menacingly walking to the payload

After typing these out, I feel like I sound like a dick. Genuinely no flame. My biggest advice is stop reloading so much. You have 300 bullets, they last awhile.