You can call DL and ask to be transferred to IT/web support. Sometimes they're able to do things for you when the website refuses.

OTOH, are you sure you need to transfer miles? Husband can book tickets for you from his account or you can get a RT ticket with one way from one account and the other direction from a different account, although this often makes international tickets cost more in both miles and fees.

Given the costs of transferring miles, it can make sense to transfer some from a credit card or hotel program (check the exchange rates) or simply buy miles directly from DL if you don't need a lot for an available award ticket you can use.

Don't procrastinate as award availability can disappear quickly.