Just sleep more often or spend some money to recharge. You don't need to do quests every day; whenever you have a new quest, it becomes on hold until you trigger the next scene, so you can progress at will.
At the market, you can buy Water or Fruit for 40 Credz each (cheaper than vending machines), which recharge 1 Mental or Physical Energy, respectively.
If you don't have much money, then play a bit more until you unlock the Museum and spend some days working there to get money without wasting Energy, then sleep. When you have enough money again, you can keep investing on Library/Gym and also spend more on Water/Fruit, or even the Theaters when you are maxed out (10 max Energy) to refill everything at once.
There's also another game you can buy at Otaku Kingdom, which will recharge 2 Energy points of each type whenever you play, but it only has 3 stages IIRC and will no longer recharge you after you complete it, just like the first game.
