Jesus people on here are such drama queens, and any attempt at creative input seem to be people wanting massive boosts or ridiculous nerfs to skills. Only minor adjustments need to be made. The rest is how good you are at your class
The reason you are getting owned by People of said classes is because they are better at their class than you are at yours, or they have a much better kit, or both. Maybe use the time you'd be complaining to figure out how best to counteract their methods?
Theres definately people around, not complaining, who have managed it. So have a go yourself.
Intended as a happy suggestion, nothing else