I have just come across some new research that links widespread E.D. in young men with the use of porn. This symptom has always been reckoned to have a physical or psychological cause, but the new research shows it can be caused by a change in brain chemistry from viewing porn. The distressing symptoms are reversible, but may take up to 5 months of not using porn. There is an excellent 17 minute video lecture by Gary Williams called The Great Porn Experiment at TEDxGlasgow. Good luck to anyone suffering, I hope this brings a solution for you.