I feel the same way! I've had some part-time jobs, but none of them worked out well, and now I can't find another one. So, I'm not the best person to ask for job advice.
However, something that might help is to focus on positives. Have you had any jobs before? That's an accomplishment. If you had a job that didn't work out well, did you learn from those mistakes? Are you doing/ did you do well in school? Can you take more classes to improve your chance of getting hired? Part of finding a job involves remaining positive and not giving up. Not that I always manage to stay positive, but it's something to think about.