Dear LG,
Very often during sex, after a few [4-7] minutes, I begin to go soft. I have never had difficulty with resuscitation by administering a few min of self manipulation.
Needless to say, this has caused some frustration, and also concern on my part.
Your insight is appreciated,

Dear brother Lee,

Without knowing your age, your general health, your specific issues with condoms, latex, meds, diet, etc., it's very difficult to have any insight at all.

Please write back and answer the following questions:

1. Age?
2. General health?
3. Diet?
4. Sexual m.o. with and without condom?
5. Duration of paid sex appointment?
6. Does the behavior occur with specific individuals or ALL women?
7. Any substances involved?
9. How long has the problem been going on?
10. How often do you masturbate?
11. What does "sex" mean? Penile-vaginal, fellatio, manual masturbation by provider?

Answers to those questions might assist,
The Love Goddess

1. Age?         41
2. General health?  Excellent--workout daily, slender, athletic, nonsmoker
3. Diet?   Low fat
4. Sexual m.o. with and without condom?  Happens both with and without.
5. Duration of paid sex appointment? 1 hr; [also happens with SO]
6. Does the behavior occur with specific individuals or ALL women?   Its occurrence is unpredictable, perhaps 30% of all encounters. With SO, it also occurs about 30% of the time.
7. Any substances involved? Occ. a glass of wine
9. How long has the problem been going on? 2 yrs
10. How often do you masturbate? lees than 5-6x/year
11. What does "sex" mean? Penile-vaginal only

I have gone through a trial of ED meds which had no effect on the detumescence issue

Well then, brother Lee,

If it occurs less than 30% of the time, is it really something to worry about at this time? Or are you expecting a 100% performance at any given time? At the age of 41, your issue does not seem improbable. It may be an issue of performance pressure and expectations.

On the other hand, you're saying that you go soft even with ED meds? That seems very confusing. In other words, even with ED meds, you get hard, then soft after a few minutes, without a condom and no other barriers?

Then, the only possible explanation is psychogenic. I have had clients who were able to penetrate and stay hard on Viagra with providers, but with the SO,  the Viagra did nothing and alprostadil injections were necessary. If you want a guaranteed erection, that may be your next step. You will need to consult with a physician who will prescribe Muse or Caverject. That, or do some relaxation breathing exercises or meditation before sex.

Thirty percent of less than perfect erections seems quite normal and attributable to stress, mood, outside factors that aren't necessarily physical in nature.

Cut yourself some slack, no pun intended,
The Love Goddess

This could be ME.
The first thing that comes to my mind is FOCUS.  The most important sex organ is between the EARS!  We are in a very stressed world right now.  Sex should be in a bubble were all the world is blocked out. NO distractions.  White noise to block traffic.  Music should be soft enough that you do not follow lirics.  Little or no alcohol.  Enough energy to be reasonably active.  Comfortable temperature.  There should be NO breaks in the action so the stimulus remains continuous.  Have everything needed within reach.  Covers, lube, small towel.  

If you have any worries, deal with them before sex & then block them out.  Bills, work, appointments, whatever.

One last thought...  my Fav ladies always finish what we start...  by hand (lube) or whatever...  

Oh, yes, lay off masterbation for several days beforehand.  Do it yourself sex, trains the body to respond to other stimulation very different than M/F sex.  

I hope this helps, it has for me.  
skb

Happens to me over 50% of the time when using condoms. I'm fine for about 10 minutes then the little feller goes soft. I treat that as an opportunity to take a break from P/V sex and engage in some other form of exploration until things just naturally get back to P/V.

Thanks to LG, SKB, worm:

Excellent points and reassurance.
I will skip the wine and the gym on the day of.
Also, I think I am focusing too much on my duration of pleasing the lady during intercourse.
BTW, If I take a break by changing positions at the first inkling of penile collapse, I can often prevent the problem from evolving.

Brother,
The fact that this occurs covered & uncovered, is the reason I wrote the previous.  

Additionally, you describe more erection fade issue when covered.  This is not unusual.  Covers reduce sensation, but all covers are not created equal.  
First I find thin latex to be more easy to transmit sensation.  
Second, FIT.  Friction makes things happen...  causes sensation.  If you do not move against the cover you do not get friction.  Condoms come in all shapes & sizes now.  You need enough room to have some movement while gripping the shaft to keep from losing it.  

BTW if my SO uses too much lub (bareback), I get almost no friction & guess what?  Difficult time completing.  

You may have to research brands & styles to get your best condom fit.  I bring a sealed 3 pack with me on a date.  I place it silently on the bedside table & excuse myself to the bathroom.  This gives the lady time to inspect them for tampering.  I respect that she has the right to refuse to use covers I provide but none have done so to date.  I have had Fav ladies say "I have them."  I just said "I like this kind."  It was fine.  I leave any remainer behind.  

But my biggest issue is Focus.  If I am concentrating on DATY it is not uncommon for me to lose some erection.  When the focus returns to me, it may take a bit of TLC to return to full erection.  
TV or music can intrude on my concentration.  Therefore my earlier recommendations.  Add no TV to that.

Best Wishes,
skb

Too much lube definitely aggravates the problem, even sans cover.
Good tips on focusing, covers, etc.
Thanks!

Mind over Muscle? Pychogenic
Perhaps why I tend to have such a success rate for those who self diagnose ED.
Tantra ritual, ceremony and the personal practice promotes the meditation derived relaxed state mentioned.
I called it mind over muscle.
Thanks LG
you allows have very thorough answers.
DIVINE