Let’s assume for a while that your worries about the future are founded in facts. Let’s say some grand evil army is invading your little fortress and you can see them all coming with your binoculars, and you are estimating that they will reach you in another four hours. They will ravage your fortress, they will put everything to fire, they will slaughter, and they will loot. Now, what do you do? You work.
If the future as per your imagination is really threatening to be terrible, then that is all the more incentive for you to immerse yourself in the right action right now. Or would you squat and brood? “Four hours—they are coming! They are coming!” Is that what you’ll do? If the threat is indeed real, then work, and if the work is not real, then slap yourself and find some work.