Hi samtheman,
Sounds like depression to me, but mild chronic depression. have a look at dysthmia on Wikipedia
http://en.wikipedia.org/wiki/Dysthymia.
I know the feelings all too well, chronic low but not so low a mood, lost interest in what you used to enjoy etc. It's treatable I'm on the happy pill citalopram, and it's doing the job with low mood and giving me time to sort the rest out. Pop in and chat to the doc, mine was very helpful. Chatting on here is even better, I can get away with murder and people even laugh (virtually!) at my jokes.
Did used to enjoy gardening until five minutes ago; when I stabbed my heel with a sharp nail but I don't think that's linked to the depression.
ttfn
one of us