Ok I'll do it.

First death - Poor healing from the healers but still you should've stayed on either high ground or fight from some more range, imo you should only fight close-range with mccree if you are going for the flashbang kill, else take some range, remember you are very squishy due to slow mobility.

Ult before second death - That ult wasn't that great, too predictable and easy to counter, you should've perhaps save it and maybe go and flank them from the side or use high ground to ult, or even communicate with your team to keep you alive while ulting with barriers/heals.

Third death - You got ulted, cant really blame you for that, maybe more enemy ult awareness could've get you to live if you took some range from zarya but your team probably would still get wiped. So it's fine.

Missed flashbang kill after in 03:59, should've gotten it but I know its not always easy to hit a tracer headshot because even after flashbang her momentum still carries, so remember if its sometimes hard for you to headshot at close-range after flash just use right click, it got a very high fire rate and also a nice solution which will finish a squishy 200 hp or less hero.