Hello there. I can understand your concern. This could happen due to a variety of reasons. And the clinical history you have provided is also very little. Yes smoking and drinking does affect your sexual life in an adverse way. And so does stress. So these could be the reasons and for this only you can help yourself. Kindly take necessary actions. Have a high protein diet. Do pelvic floor muscle strengthning exercises. Best regards. Dr. Anil kumar jain.