Just go back to the classics man
Read philosophy
I recommend starting with Will Durant's Story of Philosophy theb maybe start with Montaigne
Do math
Lately ive been doing one proposition of euclids elements per day and it is actually fun, bought a compass from .99 store for this
Listen to your fav music
Eat your fav food (ofc dont dopamine farm)
Thats what I do now and I have felt great.