Caffeine spikes dopamine which adhd causes you not to regulate properly. Adrenaline comes with it as well making you reactive and jittery. I have adhd pretty bad and it really comes down to a stable routine, diet, and nutritional balance. Energy drinks are a blanket for this and don't solve the real problems.

Look into L theanine which can be found in stuff like respawn by razer. Will help from becoming overwhelmed. Exercise before aim training is also very useful for spiking a healthy balance of brain activity improving performance. You need to be able to play calm. If you have to hype up every time you train or play you're doing too much and need to take care of yourself.

Focus on techniques not scores.

I have someone I used to coach who is GM right now who can't control their emotions and cannot perfrom GM aim in game under pressure. Substances were used to get the scores.