The thought that "i need to feel productive to be happy" is probably stemming from the deeply ingrained feeling that you have to be productive to some degree to simply exist.

Look at some trust fund billionaires, do you think they always feel the need to be productive when they in reality can sit on their ass, blow their nose into Michal Jackson's diamond glove and fly radio controlled fullsize airplanes into mountain ranges with their feet all day if they wanted to?

Sure, i wouldn't like doing nothing all day but watching television if an option was to work 40 hours a week.

But i definitely wouldn't work 40 hours a week with healthcare, fast food, scribbling old blueprints into databases or moving stuff to the front at a supermarket, if sitting at my ass watching TV all day was an actual option without falling into deep poverty.
I probably wouldn't watch TV all day then though, i would probably do something else.

I would like to build paintball cannons that would connect to a GNSS connected drone, which had a camera + LiDAR sensor and could feed the control system for the cannon with exact coordinates to the target.
All this synchronized with body mounter LiDAR sensors (or stereo cameras) that would 3D map the playfield (like a forest) to mark in the system where obstacles like trees were, so the system would be knowing what positions were obstructed.

Another thing i'd like to do, if i could, was to make a brain scanner that could sens where you have itches, and mark in AR glasses for someone to scratch you most efficiently.

Of course i neither have the time or resources for this now, but i think it would be a fun and educational hobby for a while.