Thanks for your query.Based on the facts that you have posted it appears that you are facing problem of premature ejaculation
Your wife can conceive if you are ejaculating in her vagina during intercourse.
As regards premature ejaculation is mind related and due to performance 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
3)Take anti oxidants like Almonds 5-6 everyday..
4) Avoid alcohol and smoking