Experiencing both fatigue and sexual weakness can be linked to several factors, including hormonal imbalances (like low testosterone), high stress, poor sleep, nutritional deficiencies, or underlying conditions like diabetes. Because these symptoms have many potential causes, there is no safe, single over-the-counter medicine to self-prescribe. I highly recommend consulting a doctor. They can perform simple blood tests to check your hormone levels, thyroid, and blood sugar to find the root cause and prescribe targeted, safe treatments. In the meantime, prioritizing regular sleep, eating a balanced diet, and managing stress can significantly help improve both your energy levels and sexual health.