Hello dear Understand your concern First avoid stress and smoking as it cause erectile dysfunction. Do not think so much about your problem as it cause stress. I think smoking along with stress cause erectile dysfunction in your case. Also note other causes: Diabetes, obesity, alcohol, low testosterone, prostate enlargement, hypertension, damage to back nerve and spine problem, fatigue and relationship issue. You should consult the psychiatric/urologist and get the following test done: Blood sugar, health check up, lipid profile, CBC, ESR, semen analysis. color doppler of penile area. Doctor may give following advice: Take healthy diet and fresh fruits, quit smoking, start regular exercise like yoga and walking 30-45 minutes early in the morning, use double condoms, talk to your partner that decrease the anxiety, hold urine before urination, try women on top position, be relax while doing sex. You can use sildenafil plus paroxentine after proper evalation 30 minutes before sex if above problem doses not help. Cognitive behavioral therapy also useful. Tablet co Q and gonadil F improve sperm count also. Hope this my help you Best regards Dr. Sagar