If there's a schedule to your tiredness then can probably reschedule it. This is a lesson I've discovered to good effect. [Side note: 2-3pm is probably due to food/glucose/insulin levels - its worth investigating]

Don't be fooled by tiredness. You can be mentally tired but not physically tired. These are not opposites. You can be physically tired in one aspect but not another.

You can be mentally tired but because you like to paint, then painting will regenerate you. It will make you less tired after you paint or even better: have you now appropriately tired that you properly sleep due to that tiredness.

Tired is not tired. You be tired in one way and not in another. This blanket use of the word isn't helpful and leaves a lot of potential left behind as you sit on the couch "tired".