Sexually Active At 60 Yrs, Unable To Hold Erection. Solution For The Problem?

I am 60 yrs of age my wife 58, I am still very active sexually, we both share each other s company for most of our time, I see my issue as two-fold, I do not hold an erection too long but mastered oral ways in achieving organism for my wife, as she only wants immediate intercourse and by the time she gets aroused its game over for me, leaving her very frustrated and annoyed, now she refuses to engage in oral or foreplay and expects me to start of at full intercourse knowing full well after 4/5 mins its all over. any advise would help.