Adam, I know what you're talking about. Most days at work I wonder why I submit myself to the torture I get there, and I would consider something else if there was anything that paid anywhere close comparably, within even an hour or so drive. I agree with spasm, get a Vitamin D test done first, and then get to spending time in natural sunshine and a high-quality vitamin D supplement. Find something that is exciting to you as a hobby and DO IT frequently... I look at the local dragstrip every time I drive past and sigh, because I haven't had anything worth racing since shortly after meeting my wife. I long for the smell of race gas and burned rubber, and I think this summer I'll make it a point to make "me" time to just go and take in the smells.
In the meantime, hopefully some solace and contentment can be found that you are a valued member on this board and do much to build the knowledge base. You're not alone, and there are definitely resources available to help. See what your local VA offers as well to get you back on the right track.