Depression can make you feel this way... and if you already have a job, hobbies... it may be something bothering you inside but you don't know what it is... Do you have someone that you can talk to?
depression seems to take away all will to continue hobbies,work,family,...........and so on. Atleast my bouts w/depress. have. There's times you cant even get out of bed. it does suck. As it was preveiously suggested---get to a doctor. I understand how you feel.
I do feel guilty now for moaning about it. I have hobbies I work and I have been to the Dr and am currently on meds, but I can't get therapy untill October due to the waiting list.
Actually I'm browsing this forum again 'cause I noticed myself feeling like that.
I have a job (a better one than months ago), a girlfriend, activities I like pursuing yet I feel profoundly unhappy and uncomfortable as if my past suffering kept lingering.