Biomedical sciences applicant here. I don't know if this really applies, but my record was as terrible as it can be for a long time.

I majored in ecology, never took a biomedical science (immunology, microbiology, etc.) course in my life. I failed two classes, my overall GPA was around 3.1. I also am an alcoholic, was arrested multiple times for various things, and spent about six months in a treatment center.

It took a long time, but I really focused on what I wanted to do, and applied to probably like 30 jobs before finally landing a lab tech position with a really great PI. I worked there for four years, published some papers, got on a patent, and have a first author publication. This year I was accepted to a prestigious microbiology program (top ten in the nation).

Some people have bumps, and not everything is fast. I'm a lot older than everyone else in my cohort, but I think people respect where I've come from a lot (this is the vibe I've gotten from interviews). If you don't get what you want this year, keep working. If you don't get what you want, next year, keep working. There are no barriers that can't be overcome, and people in academia are probably more understanding than you would expect.