Is Dental Assisting worth it?

I got into a dental assisting program but now that I'm about to start, I'm having second thoughts if it's worth spending 10k+ on it. Even my dentist has advised me against it, and said the career is not worth it.
I know I would rather do something else but I'd have to spend a year upgrading my bad grades, and I'm afraid even then I might not do well enough to get into something more competitive. Plus I already wasted 2 years doing nothing.

It's been weeks of contemplating and I'm just so lost. Should I just go through with the program and maybe start upgrading after?