I'll put this very simply. I don't want to appear to be unhelpful or some kind of hater/eternal pessimist or anything similar either but when I see people who are so readily deterred from studying and pursuing medicine it automatically makes me question if they were ever serious about studying medicine in the first place.
I've encountered this theme from time to time in people who were originally determined to pursue a professional course which is known to be competitive to enter or difficult to complete. Coincidentally I have heard similar in people applying to join the armed forces or pursue other careers which aren't the type you just walk into. In talking with people the discussion basically follows the lines of: 'I wanted to do X, I did Y and and Z but...'
And then I hear the real answer, it usually appears right after the word 'but'. Something happened, some hurdle they encountered and that gave them a get out clause. I know all about this because when I was younger I fell back on a similar excuse and it limited my life in a huge range of ways and I don't mean for the better. People, especially young people who are barely out of A levels, should entirely avoid any kind of thought process which curtails the prism through which they view life. It's not helpful, it's not realistic and it certainly should not be encouraged.
Medicine is medicine. You will know if it is truly for you because you enjoyed every second of your work experience in any clinical environment to the point that you almost don't want to leave and you were buzzing about your experiences for days or weeks after. If medicine truly is your gig then the factoid of completely flunking your A levels would never deter you from it. Sure, you can work as a nurse, a midwife, a radiographer, a physiotherapist. Those are all very difficult and demanding roles which offer their own challenges and rewards, but they simply are not medicine. Not by any stretch of the imagination. Medicine is an entire other planet of content and detail in which you will bask, swim, travel and learn within. There is no game quite like it. No other course offers the same content, except through the odd peep through a window left ajar.
Exams sometimes go wrong for people on the day. It's a fact of life. But they are not the be all and end all of anything. There are lot of people who are hugely successful in life, even some of the top surgeons out there, who would happily admit they completely failed or messed up an examination or string of examinations at some stage along the line.
Anyway, if someone is now post A level at the age of barely 18-19 and thinks this is the end, it is not.
Your end goal remains the same, only your journey will be slightly different to that of others. That's ok: nobody's medical journey is the same as anyone else's anyway and it makes for a more varied profession at the end of it which is kind of the point of the whole process. The medical profession is supposed to reflect the variety of the population it serves.
If you still want to do this thing, and you truly do still want to come to Hogwarts and study our particular magic, you need to dust yourself off and get back in the saddle. You can then spend some time resitting your A levels privately OR you can take up healthcare work, learn a lot of things on the job in the real-world environment for a couple of years and then contemplate completing an Access course once you've got your head around adult life a bit and fully considered the challenge of taking on medicine as a mature student.
Either way, this is merely a bump in the road. It's going to add texture to your career, it's going to build your resilience and it's going to make you a better clinician by the end of it.