Ritalin user here, but since it's often used for the same purpose, I figured I could add my 2c.

When I don't take my meds, my brain is like a car with play on the steering rack. I try to control the car but the more play there is, the more it can jerk around and veer off from where I want to go. Compensating for it results in overreactions, irritation and exhaustion. Sometimes I feel like I just want to lie down and curl up in a fetal position wherever I am.

Some things worsen that feeling. Interruptions, task switching, social media, coffee, dealing with people. When I take my meds, it's like it reduces the fatigue and tightens up the steering and I can relax a bit and focus on driving as opposed to what frustrates me.

I get by on pretty low doses, and only take it when required, which is mostly work days.