Sexual passion, intimacy and erotic joy in marriage are crucial components of a strong relationship. So you have to take this issue, and your wife’s frustration, very seriously. But your wife’s suggestion, even if it were not halachically problematic, is not the solution.
As I wrote in “Kosher Sex,” the reason why Judaism opposes masturbation is that it depletes a husband’s desire for his wife. The more we release our sexual steam on our own, the less we can employ it to connect with the person we love. Simply stated, the sexual pleasure we derive in marriage should come from our spouse.
I counsel many husbands who are addicted to pornography. I explain to them that the main sin of porn is not even a sin of commission, doing something wrong, but rather a sin of omission, failing to do something right. In these instances, you have a husband who, rather than making passionate love to his wife, is finding erotic thrills with fantasy women on the Internet. That can’t be healthy for a marriage.
Whereas other religions see the principal purpose of sex to be procreation, and modern secularism sees sex as being principally recreational, Judaism posits sex as the main means by which a husband and wife achieve intimacy and are sewn together as bone of one bone and flesh of one flesh. So it’s got to work.
And you are correct, Judaism is insistent that a wife’s pleasure in sex is not only central to the act, but must even precede that of her husband’s.
There are many remedies that can be employed for premature ejaculation, and to be honest, you don’t need a rabbi to advise you, as there are many books available and sometimes even medical remedies. You are correct, however, in trying to marry said remedy to Jewish law because these laws are designed to ensure that the intimacy of sexuality is never compromised by its other essential component, passion.
One suggestion that immediately comes to mind, however, is not to define sex as being strictly about intercourse. You can, of course, give your wife great pleasure through long, erotic massages that she will no doubt enjoy.
Finally, you and your wife must learn to communicate about sexual matters. I fear that her refusal to have sex over something that may be slightly outside your control will leave you feeling emasculated. So, yes, she must enjoy the experience, but no, neither you nor she should give unilateral ultimatums about sex when it comes to matters that are not intentionally selfish. Rather, talk about it, work it, and go and seek counsel if you need to.