1. Your Bouncing Betty placement is god awful. You are putting them down 2 seconds after YOUR spawn point? You should place them at places enemies actual go, or use them as grenades because they throw so damn far. But for starters, I would suggest placing them in high traffic areas and doors, not your spawn point. Which leads to 2.
2. Know the high traffic areas. You check every corner except the ones that matter. Example would be when you take the left route out of blue room, you check the corner where 1 out of 25 times a guy will be, go around the car (good), but then don't even glance down the alley where they actually spawn, and you get killed. Also, once you know the high traffic areas on maps, you won't need to camp. And this leads to 3.
3. Don't camp. Not only is it just annoying as hell, it's not going to get you kills, just deaths. I saw you got a few kills in this game, but those could have been achieved buy you bouncing between blue room and the fountain in the middle as well. Also, if you camp in the same spot, they know you are there. Bouncing between two close places allows you mobility, and if you se ghost, prevents UAVs from seeing you.
4. Use you radar. At one point in the video, you were inside the gate, your teammate obviously got killed to the left, red dot pops up on your radar, and then you turn right, leading to you getting killed in the back. Glance at the radar every now and then to see where people are, and once you get the general idea where most the people are, you can figure out where to go, how to get there, and actually limit the corners you nee to check.
TL;DR Learn the maps and high traffic areas so you can run to the groups of people, not camp and wait for them. Also, put Bettys where they are useful and use the radar. Your shooting and aiming wasn't actually bad.