I need help with problem of ual phobia...?

I was born with a blockage in the tubes in my bladder. This in turn caused a condition known as Hydronephrosis in my kidneys and consequently have been left with kidney disease. The problem caused me to be incontinent throughout my school years and into adulthood and because of embarrment I never entered into a relationship until the incontinence had been cleared up. However, when I have had a relationship with a woman I have had a problem firstly with premature ejaculation and later problems. After many years discussing this with my doctor, the problem seems to be psychological. I have become so scared of being a failure when I go to bed with a woman that the problem becomes worse. I would appreciate any advice as to what to do. I am now in my fifties.