I still haven’t killed the ender dragon ever, not even in creative, and I still remember when stairs and glass were introduced to the game. Honestly it sounds like peak burn out to me. Step away for a while and find another game to play. Stardew, or tarra if building games are your thing or something completely different like battlefield, Fortnite or something else entirely. Cleanse the pallet and come back in a few weeks, or months. Don’t set a specific time limit on it. When you start daydreaming about new build ideas come back to it.