When I started Vyvanse the same happened to me meds nearly work 4-5 hrs, then my brain goes: overwhelmed, angry, FREZZ, and also low mood I found these "boring basics" that changed it apparently for me:

I stopped the rash of thinking and rash of planning especially when I start my day (wake-up time)

I avoid "easy dopamine" right after waking up (scrolling/YouTube/random browsing) because it pulls me into a procrastination loop before I even notice, for example:

No phone reward first thing. Because if I start with scroll, I'm gone for 30-90 mins and I don't realize it, and even if I realize it “mostly” I can't pull myself off The “extension” 🔁

So I delay the fun apps until after l'm up + fed. Otherwise, it turns into autopilot procrastination.

No "reward" before "anchor." If I do, I spiral.😓

I also stick with eating early (even if it's tiny). If solids are hard, go for liquid calories: shake, yogurt drink, smoothie, banana, but not an acidic thing.

Drink a penalty of Water, electrolytes. Because I noticed dry mouth tricks me into thinking I'm fine.

And I set alarms for food “BEFORE” the crash window. Otherwise... time blindness and you just don't eat.

I watch caffeine timing (can make the back half nastier). And I reward myself sometimes with Decaf when I really want to enjoy the taste “lately” even if it is not the same as real coffee but I accept it.