Am I too late to do what I need to to apply?Watch
You can get a decent score on the UKCAT with a few weeks practice (I don't think it's too late to book it, although I might me mistaken.) I highly recommend using Medify's website for practice rather than buying a book (get either 2 or 3 weeks in my opinion and practice like hell.) I would say the UKCAT is generally less straight forward than the BMAT in the questions.
If you're committed to health care, why not take a gap year to get some work experience (and if you really want dentistry resit the chemistry exams.)
There's always: radiography, nursing, occupational health, physiotherapy... etc etc