Momentum goes both ways.
Whether you find yourself in a downward spiral or with a burst of energy, the trajectory will continue as long as you continue performing the same actions.
Suppose you find yourself in a slump, lazy, or distracted. Try looking at your feedback loops. Are you going for easy pleasures or challenging rewards?
Challenges help push us forward and create an upward force. Easy pleasures can (easily) send us into a downward spiral.
A surefire way to get out of a slump is to create small wins for yourself.
Pick the slightest challenge, perhaps something you need to get done and have been putting off, and tackle it head-on.
This will give you a burst of motivation, which you can use to reverse the trajectory and tackle more challenging scenarios.
Before you know it, the forward momentum will build, and you will become unstoppable in all areas of life.