Good on the OP for sharing BUT ... in a constructive sense, what does the OP hope to get out of the question?
First up, ok, some male solidarity. UKP can be pretty good for that. Butdoes the OP just want sympathy or thoughts on how to tackle it?
I can only maybe offer a few suggestions which may or may not be of interest.
a) learn to live with it and enjoy it anyway, as some have hinted at. Nowt wrong with that by the way. A lot of guys would live to be able to last longer without coming.
b) look into options to see if anything, and what, might make a difference.
c) combine both these. That way there's less pressure and it even becomes a win-win.
It's an ongoing area of research ...
(For the technically minded)http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1765044/pdf/RIU008004_0S18.pdf
Some other things that have cum up on the forum that could perhaps be relevant are:
i) guys saying they have difficulty coming with viagra
ii) guys saying they've had normal reactions in civvie street but not with prossies.
Viagra increases erection but not always automatic desire. Cock desire. It mostly provides a hard-on which needs to be 'relieved.'
Passion in civvie street can often involve an emotional connection, desire for a person on a deeper level that is also increased by being desired, and someone who 'knows what turns you on.' Sex with prossies, by comparison can be enjoyable on an athletic level or by buying into a some supposed 'connection.'
Some experiments, observing one's own reactions, might perhaps include...
>playing around with a civvie (but that can be a big challenge for an older person and outside the area of this forum).
>masturbation -- is coming still a difficulty or not?
>periods of abstinence -- no ejaculation even with self-stimulation after not thinking about it for a three or four weeks? (bear in mind that without viagra, sexual frequency can decrease with age anyway)
>related to this in some studies is lowering of testosterone levels. The NHS has a flawed policy on testosterone replacement therapy.
Going back to the other option, enjoying it anyway, some logical possibilities:
>B2B massage (warn the prossie that you don't always come. Not uncommon and she doesn't give a fuck as long as her ego doesn't think it's a criticism of her performance.)
>Tantric sex (which doesn't involve ejaculation). The prossie version usually just means 'lingam massage' or a slow, concentrated hand job.
>Enjoying some closet perv role plays. Just think of some dirty scenario and find prossies with the intelligence and acting ability to carry them through rather than just dress up as s French maid.
Hope that is maybe useful food for thought. If not, just accept some forum best wishes to enjoy your sexual encounters. Or take up dominoes.