The job market is brutal

This is now my fifth year in the UK. As a legal immigrant who has not been able to find a graphic design-related job and has ended up working minimum wage jobs mostly in warehouses, I need your help. I want to work as a graphic designer, but I'm forced to work low-paying jobs. Am I being discriminated against because I'm an immigrant or what is happening? Ive applied to loads of jobs and still nothing.