I agree with what’s been said above however it’s also important to mention that if you have good predicted grades and have relevant experience etc then you have nothing to loose by sitting this ucat this year and applying (if you are well enough)! More than a year is plenty of time to bring your grades up for actual alevels so as long as your predicted grades are good then you should be okay.
Maybe speak to your teachers about this- every school does it differently, they may be able to give you some allowance especially if your grades have been good previously.
Another option is just focusing purely on alevels for now and then taking a gap year where you can do your ucat/work experience so that you can focus on making your grades good.
Also, some unis offer ‘transfers’ where you join a course for one year then can transfer onto medicine or you can do the 3 year undergrad and be guaranteed a med interview (I believe Exeter does this- I could be wrong). Maybe look into backup courses like biomedical/neuroscience/biology then look into grad entry?
Like mentioned, you can look into ‘Extenuating circumstances’, some unis will accept this.
Also maybe look at the other requirements for contextual offers at particular unis, your school/postcode/parents not going to uni may help with this- I recommend looking around uni websites and checking as some are more lenient than others.
Also potentially seeing if you can do any widening participation programmes or summer schools which will qualify you.
Overall, there are several options, I recommend speaking with your teachers/head of years. If you can get good predicted grades then really focus on smashing your UCAT and then on alevels- you have plenty of time if you are in year 12, try not to beat yourself up about it! It sounds like you are super resilient which is essential for a career in medicine anyway and all of this is experience which you can eventually talk about at interview.
I know lots of people in med who took gap years or several gap years so that option is always there and maybe one to consider-there are lots of pros to doing so!
Good luck with everything and let me know if you have any questions 😊