You might have a bit of a feedback loop going. Your body craves dopamine and gets it from being horny so when it need dopamine it also makes you horny.

I have adhd and i found my boy-clitoris way before my parents expected and somehow built a habit jacking off playing video games before I could even physically ejaculate. So now when I’m playing a game I still get the urge to stop and jack off simply cuz of how they got associated.