I would worry less about matching rads at this point and worry more about figuring out how to change your habits and address what caused you to fail. If you can do that, then this will be akin to an upward trend in your premed grades. Not ideal and may hold you back from some programs, but ultimately just a blip on your resume if you show improvement. You can’t just assume you’ll do really well in classes “starting now” and will do really well on step 2. Don’t worry about radiology research or shadowing or any of that. Figure out what your issues are and really work on becoming a better student. No amount of research can overcome bad test taking or laziness.