I understand the near paralyzing depression, which will include some feeling sorry for yourself (at least mine does).
I want to offer a challenge to you in your thought about the importance of being in a job where God can use you. There are VERY few jobs where he can't use you. You see, one of our purposes here is to be in fellowship with others to have an influence on them. Sometimes this influence is unspoken, it's in our actions and our character.
Regarding looking for a job, if you are a Bible reader, read Exodus 35:31-35. It will give you encouragement that all different kinds of jobs are pleasing to God.
The way you are feeling is absolutely NORMAL. In fact, I'd say you are doing pretty well.
