But another thing that's not really talked about is fatigue levels - if you've spent time on benefits, you don't really do much physically and mentally and work sure as the Pope's a Catholic changes that. You now find yourself tired, pessimistic and generally rueing the situation you are in - but keep at it.
If the work is something you truly cannot stomache, like your boss is a real sadistic arsehole / cow who threatens you with violence etc like one of mine did - then by all means quit. While I spent another two years desperately seeking a new job after that - it's not a decision that I come to regret. (She did make me vomit with nerves every day I had to go to work there, so I think I made the right decision.)
Keep your chin up, fella. You're just merely tired from going between a world of benefits and a world of work.

Should you wish to PM me, I'd be happy to lend you an ear.