For what it's worth, here is my post on The Loss of the Auto-Erection, about facing the changes in male physical arousal that inevitably occur as one grows older.
I got my education on the topic from The New Male Sexuality, written by Bernie Zilbergeld, rather than any particular website. It's a very good read, for BOTH men and the women who want to understand them.
Take care,
-- B.
Me 50, W 45, M for 26 yrs S25, D23, S13, S10 20+ year SSM; recovery began Oct 2007