Recently , As On 22/04/2016 I Got Married To A

Recently , as on 22/04/2016 I got married to a healthy girl. And I am a slim fit 30 yrs old. I am not getting erection in bed..feeling helpless on bed.Sometimes I got erected but while intercourse...its shrinked to small. Now a days I am unable face my wife. Last four days I havenot done any sex with my wife.
Before marriage , I had no sex experience.
Plz plz guide me.

Binod
Kadapa AP
INDIA