Hello Thanks for your query.Based on the facts that you have posted it appears that you have problem of getting ejaculation even with slight sexual stimulation. This is very common in unmarried people and is due to anxiety. Following measure will help you to boost up your confidence and getting good erection.and delay ejaculation. 1) Practice regular exercise for 45 minutes followed by meditation for 1/2 an hour in the morning. 2) Take high protein diet rich in vegetables and fruits and Vitamin A,C,D,E. 3)Take anti oxidants like Almonds 5-6 everyday.. 4) Avoid alcohol and smoking.. As regards less semen volume on second attempt, it takes 24 -36 hours for testicles and prostate to form 2-4 ml of semen so it is but natural for any one to get less semen within 5-6 hours after first ejaculation.. Dr.Patil.