Believe that you do bring value and skills to a prospective employer. Spend some time thinking about what you accomplished at your previous jobs. Make a list and review it again and again. This will improve your attitude and self-confidence and will help you at your interview. Don't blame other people for your previous work problems.
Responsible employees are in demand.
Interviewers do not like candidates who make excuses. Discuss your accomplishments instead of the negative aspects of your previous job. If you have to talk about why the job did not work out, discuss what you learned from the experience that will make you a better employee in the future. Keep searching and don't get discouraged. The reason you did not get a job may have absolutely nothing to do with you.