Actually, I think you have it backwards. You say *you* need to be needed. But my objective POV says you really don't want/need your wife. This is classic denial and transference of YOUR issue onto her. Check your navel on this:
"The more I thought about it, the more I knew that she wouldn't be into strap ons or gender roleplay. She would sympathize with me but not be able to carry it out, and *if she tried it wouldn't be exciting it would be awkard*. But you're right that the only way forward need not be cheating. As I said before, one of few options that isn't on the table is cheating."
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh