Howdy @Captain24 😋
I think 'undoing' those faulty childhood beliefs is a process - not some magic thought or action that will suddenly 'click', but the result of gentle, repeated shifts in how you are choosing to see things. Very simple example would be trying to consciously (and preferably very gently, and without shaming) remind yourself that rest and relaxation are NOT to be earned because they're essential to survival. You don't need to 'earn' brushing your teeth or drinking water; resting is just another daily habit - not a reward for working hard.
Maybe also something like... if you usually reward something like 'getting all household cleaning tasks done' with resting, change the reward to something that's actually a treat, and practice also taking the time to rest even if you haven't finished the list for the day. Like 'okay if I wanna earn my (hot chocolate, bubble bath, indulgent snack, etc) tonight I gotta finish at least all the dishes and laundry' but then no matter what, you are taking some me time and doing some Lego; only difference is whether you also earned dessert!
These are just thoughts on things to try, I think you will figure out your own way. Just remember these changes don't happen overnight.
Oh a clean fridge!! Love that! I managed to clear off my bathroom sink last night, and it really does bring on a sense of calm when there's a nice clean white surface and not a whole bunch of visual noise 😅
Did you figure out how to do the paint by numbers? I would personally go colour by colour but that's just cos I would get all confused with too many paints on the go - and make way more of a mess! Like I'd probably accidentally dip the red paintbrush in the yellow paint pot and then oopsie my sunflowers are orange now 🤣