What should I do if I can't get a job?

Well, for starters ring around in your area and see if anyone needs someone, if you can't get a job for physical or mental reasons then perhaps volunteer somewhere to do something with your time and help your community out. You could always look into self employment options like writing books or doing a course online to get you in the door for a job, if you are not working then volunteer work is a great start. It helps. There is another option- ringing around and asking if you can have a trial period were you work for free for a couple of weeks and see if they want to employ you after that?