fringe pond
Aim training is mentally fatiguing. Take a good break after training before hopping in game or train after your game.
You are also more likely to overanalyze your aim in-game, which is not what you want. People tend to do this after starting aim training.
Aiming is subconscious, and not conscious. Focus on anything else other than your aim. You cannot micro manage your aim. You just need to let your subconscious do its thing and put your focus where it matters.
That second part is the biggest issue that many people face. Aim trainers do not and cannot make you bad, however, people start to shift their focus to purerly their aim and that is an issue.
Also do note in general that performance isn't linear. You cannot expect to play the exact same every day.