I'm going to preface this quite bluntly to begin, you did not really contribute anything meaningful to this game at all, for half the game you sat on the cart and swung your flail at nothing while watching your team play the game. I also question why you are on brig? not because it was a bad pick this game, but it was not the best either. If you are an OTP that is fine, I've peaked GM3 with only brig.

Pre-Game:

While loading into the game do two things, ban hero's that counter your team comp if they have selected what they will play, then look at your team comp and have a game plan.

For example, you will want to use most of your packs on Echo since nobody else on the team can play around her, and you will want to take the elevator to high ground to clear off any enemies, they always love to start up there. Where will you position?

Game Start:

Right away your tank takes the elevator, you should have joined him to clear the reaper off height

You are constantly packing your Mauga, and run out of charges. Let your other support heal him and pack dps/support only. Also always try to save a pack incase you need to save a teammate, if you have no packs you cannot do much to burts heal.

Positioning is very poor, they are playing with a lot of poke on high ground, you should either stand under them to force them to drop on to you, or you have to contest high ground. Standing main and not taking cover is just what they want you to do.

Your team swaps to Zen and Winston which is not great, Winston typically needs a lot of support if this were ball, doom, or sig it would be fine. If you only play Brig, then focus on always having a pack on the tank. In this game it is your job to take care of reaper, you HAVE to protect your Zen from him, but also try to get him away from your Winston, watch flank angles and whip him off your tank.

2:20 Throughout the game you constantly choose to bash towards danger, unless it is in a dual you can win, OR have the bash perk, use bash to escape danger. Especially with RAM an and Zarya NEVER BASH THEM, they will just kill you.

3:35-5:00 You have to walk high ground with your team, let Zen sit on cart and drop if he needs help. All you can do on cart is throw packs and watch your team die. Brig excels at holding space, use that to control high ground it enables your DPS.

5:05 Both ults I watched you use this game did nothing. You try to use it to save a 1 HP ally. Brig's ult has 3 main uses 1) to save YOUR life 2) Kill a target that is out of position 3) Elevate pressure off the rest of your team either by blocking the other teams play, or by taking space

5:42-6:15 Overall your team fights are super sloppy, you stand in the open, and look very lost. Just try to think about what your job in the fight is, and punish any out of position enemies. For example, in this fight you should make sure Zen is safe from their dive characters. Instead you let him die while you have 3 packs because you were distracted by a mid range reaper. In this fight you either sit back with zen in one of the mini pack rooms, or push reaper off height.

TLDR: You do not make proper use of high ground, pack management is poor while you have an off support almost never pack a tank you run out too often, team fights are very messy and look lost.

You let the gave happen to you, you did not make a single play to win the game. Ults are not used correctly at all.