Different Types of Tasks

On day 8 here. I have been finding that there are certain things I can do that are getting easier and feel pretty good:

• Socializing. Not that I WANT to socialize in the moment, but I can force myself. Feels like my brain is firing effectively and I can hold conversations and feel pretty good about interactions.
• Related to the above, work meetings feel pretty doable, just talking through things, giving updates, etc.
• Simple chores / errands. I can put one foot in front of the other and just take it slow, don't overextend, and seems to be ok.
• Well defined tasks like booking travel "I need to take a trip between X and Y, let me look for itineraries that will make sense."

However when it's time to turn my attention to anything complex / requiring a balance of broad thinking / creativity + maintaining focus for some time, it just makes my head hurt. I'm staring at the computer screen and my mind feels empty after like 5-10 minutes. Get tired super quickly and feel like I need to lay down. Unfortunately, this is the type of thinking that's often required of me to be productive at work.

How are you all doing with different types of tasks? When did you find the creative / focused work starting to get back to normal?