B.H.
I think he should also see a Dr. You did mention that it has gotten worse so whatever is causing the problem it does not seem that it will resolve on its on. Has he been under stress? It could be a combination of stress and a medical situation. I heard that when men are having this problem they stress out over if it's going to happen again and this only makes the problem worse.
As a women I also go through this form of stress sometimes and I could just not be in the mood at all for a few weeks at a time. i believe for me its stress. Trying to be the perfect employee, mother, wife, and house keeper gets me down sometimes and I have those times where I just want to be left alone and by myself.
Hope that you both get through this.