Keep in mind that only about the bottom third of the vagina has a significant number of nerve endings so it may not be unusual that you feel little or nothing during the actual intercourse. FCL's suggestions are good ones as they encourage more pressure toward the ares with more nerves as well as (if leaning forward) closer to the clitoris.
Have you simply asked her why she no longer wishes romance (even without intimacy) with you.
Unless she is honest with you regarding these matters, an internet forum can only provide vague guesses and perhaps less than hopeful suggestions on what might be the underlying causes of what has happened to lead to this in your marriage.
Not to point out the obvious but the fact that your wife has lost her interest is sexual contact secondary to her surgical menopause and her inability to take hormone replace therapy and your diminished interest in sex secondary to ED might not be such a devastating issue in this relationship.
What often causes problems in a relationship is when one partner wishes to remain sexually active (you) and the other does not (the wife).
What, exactly, are you asking? Are you wondering how to make the wife again interested in sex with you? Since you have received her response when you brought the subject up, it doubtful you can "make" her change her mind.
You can suggest outside sexual contacts for yourself (if that is an option you both can agree on) or you can return to your internet porn and masturbation with the help of medication as before.
The bottom line (as it has previously been mentioned here) is that the person with the lowest sexual drive is the one who controls this area in a relationship. Unless she is willing to "work" with you (so to speak) not a lot is likely to happen.
The issue (from an older females point of view) is that a woman who is post menopausal will still understand that her male partner has a sex drive and may be willing to experience intimacy with him as long as the expectation that she not achieve an orgasm be placed on her as this may be very difficult for her. For many men, however, it's the joy of giving their partner satisfaction that is as important to them as their own needs being met. In the end, the frustration of attempting this simply turns the female off from even wishing to be put in the position of any intimacy that involves sexual contact.