Hello from Minnesota, Sirensong18: First off, let me say your post is not at all inappropriate for either PC in general or this forum in particular. One additional forum you might consider writing about your concerns in, if you haven't already is: Women Fucused Support:

Women-Focused Support - Forums at Psych Central

One thing I know happens, over time, is relationships change. I'm probably not telling you anything you don't already know. So perhaps this is at least part of what's going on. If so, participating in some couples counseling might be of benefit. It is also true, I believe that worry over this sort of thing tends to produce a "snowball effect". Some little thing happens, you become concerned. This concern causes you to begin to worry, which makes you worry all the more, etc.

The other possibility though, it seems to me is that there could be something going on related to your hormone levels that a standard blood test would not pick up. As such, I wonder if there might be some value in you seeing an endocrinologist.

As I'm sure you realize, there aren't likely going to be any easy answers here. It's a matter of thoroughly investigating all of the different possibilities. The trick, though, is going to be to remain calm during this process so as not to aggravate the situation any more than it already is. Open communication between you & your husband will also be important & this is where couples counseling may be important.

In terms of things you can do yourself, now, you might look into such things as meditation, yoga, different varieties of physical exercise, etc., just all of those things that we all hear about that can help to reduce stress. (By the way, speaking of stress, are you employed? If so, is your work environment stressful? Could this be a factor?) Good luck with this process!