Underwhelming work isn't a luxury problem

I work as a Founder's Associate at a small company. On paper, interesting. In reality, 80% administrative tasks that require 20% of my cognitive capacity. Tasks that take 2 hours stretched across 8 because there isn't enough work, or I simply can't get my mind to work faster on the boring tasks because I drift off so often. **What I can't make anyone understand: This is more exhausting than any challenging job I've ever had.** When I say I'm struggling, people list what I should be grateful for - flexible hours, nice colleagues, and a decent salary. All true. But sitting at my desk with nothing meaningful to do feels like slowly suffocating. Give me a choice between a multi-hour mountain pass cycling tour or a wellness spa day, I'll choose the climb every time. Physical exhaustion from pushing limits feels restorative. "Relaxation" with nothing (meaningful) to do? That's torture. My brain needs complexity, novelty, and challenge. Without it, my coping mechanisms fail. Procrastination leaks into everything. Basic tasks at home feel impossible. The worst part: When I explain this, people think I'm humble-bragging. My father asked if I'm "just bored" and if the solution can be a hobby. He doesn't get that this isn't about entertainment. It's about my brain needing adequate stimulation to function. I stayed too long, was promised development that never came, am too good at masking to realize how bad it got. Now I'm planning my exit, but the exhaustion makes even that monumental. I'm not looking for advice on quitting - I know I need to. I simply don't understand why people can't grasp that underwhelming work isn't a luxury problem. It's genuinely destroying me.