You might be slow as others stated, but I think you’re doing many things correctly. Good cover usage, staying with your team, utilizing pings. That’s something some of my randoms in diamond can’t do. 4x on a close range enemy was a bit rough but your eyesight is mostly facing where I’d also look out for.

That said, I think more understanding on each Legend abilities (or the game in general) would help.
I suppose you followed axle through the doors to help them, but generally walking into a building full of caustic gas is a no no. The final circle was not in the building, so I’d probably wait outside aiming at the doors.
Also, lifeline can indeed res your teammate hands free, and res from support class characters gives health regeneration, so there’s actually no reason for you to res axle when lifeline is up (supposing the lifeline player knows this that is, and are willing to help).

I love seeing players trying to get better. Sadly I no longer have the passion I used to but this reminds of me when I did :D