Feeling very weak and unmotivated in the morning can happen due to several common reasons, such as poor sleep, stress, low energy levels, or nutritional deficiencies (especially vitamin D, B12, or iron). Since you already have low vitamin D, that itself can contribute to fatigue and low mood. To improve this, try maintaining a regular sleep schedule, getting some morning sunlight, eating a balanced breakfast, and staying hydrated. Light exercise, like a short walk, can also boost energy and mood. Managing stress and reducing screen time at night may help improve sleep quality.