How to maintain an errection?

I am 49 yrs of age, and married, and maintaining an errection is becoming wose by the day, and the interest to have sex is less by the day. I am no taking viagra 100mg when I am feeling like having sex, which is about once in a month, I can get errection fine, but lose the errection fast, what could I do to maintain the errection?

[NOHARD]

Hi G, Look I will send you to posts, of the things that got me back in the action, from ED and now in recovery, its all simple herbs and a hormone all safe if you just stick to the amounts and please do take the weekly and 12th week breaks the important, the posts are on another site for ED. the first post is titaled DRUGS VERSUS HERBS, HERBS MY CHOICE, if you google that, it will take to were it is.
Good Luck