Howdy Jordan,
Welcome to the site. I'm sorry you had to find us.
I was very happy to read he is under a doctor's care for his depression. The symptoms manifest themselves differently between the genders which is why it goes under diagnosed in men.
Hopefully you have read some books or checked out a few websites on depression on men. I am guessing you must have done some research because that was a damn good observation on your part to recoginize it.

Is he also seeing a counsellor along with taking the meds?
Now you need to do the same thing with affair recovery. Read. Also perhaps suggest marriage counselling to your H.
Here are a few recommended books:
• The Monogamy Myth by Peggy Vaughan
• After the Affair by Janis Abrahms-Spring
• Not Just Friends by Dr. Shirley Glass
There is a complete listing of reading material in the announcements and policies forum.
Its important you take care of yourself: Sleep, eat and exercise. If you find YOU need help please see a doc also. Its very normal for a BS(betrayed spouse) to have to deal with their own depression after discovering their spouse's infidelity.
Once again...welcome.
Regards,
Tex
P.S. I am going to copy your post to the Discovery Recovery Forum so you'll receive more responses.