The blank, emotionless feeling you describe is called
anhedonia, it's very common in chronic major depression and Bipolar.
IT IS NOT PERMANENT.
Ever have to reboot your computer after a crash? That's what anhedonia is, your brain rebooting.
As for the high DHEA level -
YES it might be the cause your new depressive symptoms! You need to see a really good Endocrinologist. Don't go to a quack, they make their money doing bogus testing, and after all that you'll end up right back at the starting line. (I've been down that road a few times

) Try the nearest non-profit or teaching hospital, they usually have the best docs.
Elevated DHEA levels could mean something isn't right with the adrenal glands, like a benign tumor, cyst or adrenal hyperplasia, (because it causes elevated
male hormones, milder forms of AH are sometimes missed it boys - there's also an adult onset AH). http://www.nlm.nih.gov/medlineplus/ency/article/000411.htm