Thanks for your query.Based on the facts that you have posted it appears that you have oligospermia
You are trying to impregnate your wife since one year.
You have not posted detail report of your semen analysis
as far as motility of the sperms is concerned which is very important factor in fertilisation of a female egg.
The size of the Penis is not relevant factor to conceive.
Consult qualified infertility
Specialist for detail evaluation an further advice.