[Rury]

It's hard to stay motivated/sharp if you feel sick, fatigued, achey, etc. So I recommend taking a close look at your health... more specifically how you actually physically feel day to day, alongside looking for potential causes. Keep a health journal if you have to. Believe it or not, most people don't realize how some things subtly affect them.

Take this for example. Every couple of weeks or so, I noticed my stomach would ache, and bowel movements would burn. Wasn't sure why, but it turns out, it entirely coincided with me chewing gum or lying down after a large meal. Ceasing to do these things removed these acid reflux symptoms I'd occasionally get. Now I don't have this problem anymore.

Another example. I use to get migraines with aura almost every weekend. Again, wasn't sure why until I figured out it was due to my caffeine consumption. I use to drink coffee during weekdays at work, but would avoid caffeine otherwise. This meant I would undergo a caffeine withdrawal every weekend, and it in turn would trigger my migraines. So I cut out all caffeine from my diet (including chocolate) 2 years ago, and I haven't had a migraine since. I now sleep easier, focus better, and my mood is more stable.

Both of these changes have improved how I feel, which in turn have improved my stress tolerance and motivation for things, which I think has helped me on cognitive tasks. Maybe there are similar changes you can find and make.