Ur testosterone level is normal. Erectile Dysfunction.. It is very common now a days..Risk factors include- diabetes, heart ds, kidney ds,hyperlipidemia, thyroid ds, obesity. If u dont have ny of these then do regular cardio excercise for 30 mins atleast, eat healthy nutricious diet and quit smoking n alcohal. After this u can try Sildenafil or Tadalafil before intercourse.

You need to do other investigations and a counselling session to know the cause for your dysfunction. Based on that only I can put on some medicines... or prefer psychological/ behavioural therapy