Motivation is within your own power to create. It isn’t handed out willy-nilly by the universe. To get motivated, you need something to inspire you. The only way to identify what will inspire you is to do the introspective work to get to know yourself really well. Learn what you’re passionate about, and chart a course for a cause outside of yourself — your own personal vision.
Is your motivation for achieving your vision extrinsic or intrinsic? Are you motivated to it by “carrot and stick” consequences, or the mere hope of tangible gain? Or is it intrinsic, a vision based on your values, that is burning in your core, demanding fulfillment? Extrinsic motivation is superficial and typically less enduring. If you’re counting on extrinsics to keep you motivated, you may cycle up and down. Your motivation will be more steady if you shift your motivation to intrinsic — to values that are more in line with your psyche.
Spend the time and energy to be clear about your vision. If you lack confidence in your vision, introspect to determine why that might be. Do you need to better clarify the specifics of your vision, or do you need to find a new one about which you can be passionate?