I am going to be married soon but I am scared of SEX.What to do?

I am getting married very soon.My organ size is very small compared to my friends.Would i be able to satisfy my wife?

I mastrubate very often.Will it affect my sexual life after marriage?

I am a middle aged healthy man still desire is low.What can be done?

I get orgasm rarely. What can be done to have it simultaneously?

I am healthy man married since last 15 years.Now a days i feel low desire and erection and not able to satisfy my wife sexually.What can be done to revitalize my sex life?