I also tend towards being a fairly unmotivated person, my brain is short on dopamine that's why I have an addictive personality and can get addicted to things that others don't. Best way to regain motivation is increase dopamine levels in your brain. You can do this without stimulants by eating a balanced diet rich with protein and exercising in the morning. The amino acid tyrosine can be found in peanuts, almonds, avocados, milk, cheese, yogurt, bananas, sesame seeds and soy products. Optimistically you'd exercise for 15-20 minutes so you'll want to start this off by doing a warm up routine, then stretching, some body only workouts and stretching when you are done. Hope you feel better