While the game can have legitimate balance issues due to the fact that it’s a Hero shooter as many have already stated if you’re having persistent and frustrating problems dealing with one character class those problems are likely to be due to the skill level of the player using it or due to your current character choice or tactics being ill suited for that characters play style and not because the character you keep getting vanquished by is broken.
Instead of calling for a nerf you should try to adjust your own tactics or character choices to compensate first.