If you are taking an anti-depressant along with a stimulant (many ADD patients do this), you are having a situation wherein your excess serotonin (result of anti-depressant) is pushing away the dopamine.  Hence, the diminishing sexual drive. 

Your situation must improve if you increase your dopamine stimulation (drug, supplement...) as well.  However, this is something you MUST do under the supervision of a knowledeable doctor.

Besides, if you get on a relatively hefty dosage (about 2g EPA+DHA) of good quality Omega-3, your need for antidepressant dosage must come down.  But still, that alone is not going to help with your libido issue very much.

If you get on intense aerobics, over a period of time, you are very likely to be able to wean off your antidepressant. 

Till any of this works out, it is important for your husband to know, if he already does not have awareness, that the drop in libido is very real like a paralized hand or leg.