Several factors may cause this problem. Physical factors such as fatigue or low stamina, underlying medical conditions like diabetes, heart disease, high blood pressure, or low testosterone, and psychological factors including stress, anxiety, or relationship issues can all contribute. Since this has persisted for a year, it is essential to consult a doctor, preferably a urologist or sexual health specialist, who can evaluate your health, identify any underlying causes, and recommend appropriate treatment such as lifestyle changes, therapy, or medications. Self-treatment is not advised, as addressing the root cause is essential for long-term improvement.