I think everyone has purpose in life..even aspies..when we feel that we lack purpose we become unhappy. Especcially us because we are so cool..lol and I can say that..we need to find purpose..if you cant find it at your job..find it esle where.
I'm actually unemployed and have been so for 6 months now. Fortunately, this is an option I had, since currently my husband makes enough money to pay rent at least. I had to quit my last job before I could stand trying to look for a new job. I'm not suggesting that. It is pretty easy to get unmotivated when one is sitting at home just looking for work. There is only so much of that one can do each day.
I think the best idea is to take some vacation or sick time off work and spend it to relax a little. Then figure out what kind of job you want and work on the resume and all that.
I don't suggest trying to stay in a job that doesn't work for you. I don't think that is healthy for anyone. You don't have to have the perfect job, but if your work doesn't play to your strengths, you will just feel wasted.