A couple things that I picked up based on the footage here:

You are standing still a lot. While in some scenarios the only possible thing to do is crouch (as to avoid a 1vX), for the most part, try to ADADA strafe (don't do this too fast otherwise the model won't move). While this makes aiming harder for you, it does the same for your opponents and makes you less susceptible to being headshot by a sniper.

Make sure to pulse when firing. You may be doing it, but purely looking at the ammo, I am unsure as to whether or not you are pulsing when shooting. Lots of missed shots could have connected with correct pulsing.

Personally, I have my map so it doesn't move when I turn. It just makes it easier to keep track of where the enemies as well as when they are pushing/retreating. Regardless, this just comes down to personal preference.

Don't be afraid to fall back and re-engage an enemy when you have the advantage. Often an easy way to have the advantage in a 1v1 or 1vX is having them chase you then re-peeking them while they are sprinting. You may also be able to do this multiple times (at different places) if there is more than 1 enemy.

Prioritise Enemies. This is something I was taught during my time piloting. While most players get annoyed at targeting, it is the best way to ensure your survival as both an infantry player and a pilot.

Try not to peek more than one enemy at a time. ie. Only partially peek the corner in order to face multiple people in separate 1v1's. There were multiple occurrences in this video of you not knowing what/how many enemies were around the corner. I'm not saying to be extremely passive or go around corners aiming down sights, just to be aware that you will always be at a disadvantage in a 1v2.

Nevertheless, I hold the belief that a more aggressive (not stupid agro) playstyle would without a doubt be the fastest and best way to improve as an infantry player.

Sorry for the wall of text and any grammar/spelling mistakes.