not sure if i am re-iterating the obvious, but if I were you I won't quit (at least in this emotional state). My recipe would be:
1. Sit down with a beer, pen and paper 2. Figure out what is the exciting tech that I want to work on 3. Do I have skills for bullet 2 4. If no can I learn it with my day job (something as trivial as writing 'hello world' in a new language) 5. Communicate (talk to a lot of experts in the target technology/industry/area of interest) 6. Generally the above steps should be sufficient to convince me what I want to do. Here one can probably take a break or ask the contacts from bullet 5 to help make a transition.
Obviously, like all plans this might not work ;), but I would start gaining better control of my life/career/aspirations.
Hope this helps... Cheers!