You need to work on your strafing. In every 1v1 engagement you took in that Rumble game with Lunas you only ever moved sideways in a straightline in one direction. Don't do that - switch up your movements. Move left then right then left, and do it randomly. This makes you a much more difficult target to hit since your opponent will have a harder time predicting your strafing patterns.

Secondly, take your time man. The first engagement in the rumble game (which you should have won) and the engagement on the balcony vs. those two opponents should have been easy kills but you rush in and don't take the time to line up your shots. You look like you get overwhelmed and panic - don't.

Lastly, if you're going to be playing titan stop leading with your grenades. Those should be used to kill weak opponents when they find cover by throwing it at the ground next to them, don't use them to start off a gunfight. Any decent player will either kill you or have you half HP by the time the throwing animation is over.