A mismatch in sex drives is an issue that isn't likely to go away, but only get amplified with time. If he feels you two are having enough sex and isn't interested in more, you are at a stalemate. Were you with him during a less busy (ie. tired) time? How much of that (busy, tired) do you think is the problem here?

Having an affair is only going to breakup the relationship, either now or in the future.

I don't think wanting daily sex means your hormones are off, and maybe if you didn't have BDD, you'd still have a high sex drive. Nothing wrong with a woman wanting and needing frequent sex.

But an affair will solve nothing (I see you said you do not want to have an affair).

I'm sorry, I don't have any answers.