The answer is true internal belief. Tell yourself multiple times every day "I'm going to get a job doing X, and will do my best at that job. If I do my best I will be successful"
Mind conditioning, just like a sprinter would do for their body, you do for your mind.
You may not see immediate results. In fact it is easier to produce negative emotion than a positive one. For every 'I'm worthless and can't get a job' thought you, gotta have 3 'I'm better than that. I want, and will get X out of my life' thoughts.
Good luck anon, use this advice wisely. It is a very powerful mechanism and can be used for great good, and evil.