Hi, have read your problem and will try to guide you to the maximum.
For successful insertion of the penis into the vagina, there are two main factors (apart from the normalcy of genital organs) :
1. The woman should relax her vagina and not contract it at the time of insertion.
2. The penis should be fully erect. Placid penis cannot enter the vagina.
If during insertion the woman contracts her vagina in resistance,
nervousness peeps into the man's mind and erection may go.
Attempt to insert the penis in dry vagina is painful and uncomfortable to both. It may result in loosing the erection. Use of lubricant is always helpful in such conditions. Use only water-based lubricants or vaginal jellies available in the market. Oil-based lubricants are harmful to the woman's genital organs and condom if used.
If the penile erection is lost, oral stimulation also is known to stimulate the man.
A device called as pubic ring is available in market. This is to be fitted at the root of the penis which causes and maintains the erection of penis.
There are many causes of erectile dysfunction; the most common being
diabetes mellitus. Please get your husbands urine and if needed blood examined for diabetes. Low
testosterone levels are also responsible for erectile problems. You may with the advice of your physician get these tests performed and get the condition treated if any.
If you contact me by direct question after your husband's investigations, we can discuss further on the issue. However, I feel the information and guidance provided in this communication will help you to some extent to get over the problem.