I think it would first be important to determine whether or not you have actual damage to your braind and how bad it actually is. Without actual testing you will never know whether or not your brain was affected.

Purely guessing here but I believe the damage you’re referring to is mostly damage to the prefontal cortex (the part that’s mainly responsible for focus, motivation, planning and regulating emotions). Uppers, which are drugs like methylphenidate, speed, adderall, cocaine etc., do have effects on this area of the brain, giving it basically a higher tolerance for hormones. In short this means that these drugs very suddenly bring a lot of hormones like dopamine etc to this area, causing you to feel happier, more focussed etc. If you take these drugs long enough you will raise the tolerance of these areas. If you then suddenly stop taking these drugs, the natural amount of hormones you produce just isn’t enough to have an effect.

It’s not completely certain this change is permanent or not, the subject is still being studied really. But it appears to change the way this part of the brain works, especially when you take it at a younger age.

How to deal with it? Depends on the severity of the ‘damage’. Based on your post history and you being here, you don’t appear to have severe brain damage lol. Don’t worry about that.

And don’t beat yourself up for your past. If I had done everything perfectly up until now my life would’ve been different, but I also wouldn’t have learned from my mistakes. Me not eating that one hamburger ten years ago may have completely changed my life, but I don’t know that. Rather, learn from your past mistakes and apply your lessons learned to future decisions. You will never know what the perfect way forward will be, nor will there ever be one perfect way forward.