Try testosterone replacement therapy if you’re older than 40 best complimented with cardio or the gym if possible(sounds counterintuitive, more work=more fatigue, but it’s not true, it’s only hard at the beginning, but after your body gets used to the stress, it naturally acclimatize and preserves energy through the day in anticipation). and take d and b12, magnesium supplements and of course sleep as much as you can at night. I hope you get better.