I don't understand how people do well on the UKCAT

Try watching some videos on the sections you are struggling with on youtube. I was struggling a lot with AR when I first started practising and found some decent advice on youtube for tackling that section. If you are struggling with your maths in QR then I really recommend going through the GCSE Bitesize stuff as a refresher.

As difficult as it sounds try not to stress too much over the exam as it only causes extra distraction, you can only do your best and if it isn't enough this year there will be further opportunities in the future! Focus on practising and improving and not speculating. My exam is 3 weeks away too, relax it is plenty of time to continue to improve.

How much practise are you doing per day? Are you using medify (most I speak to swear by it and I love it!)?

Firstly, as a response to your original post, is the main problem that you have inaccuracy or timing for AR and QR? If accuracy in the problem, then I would suggest marking your practice questions ridiculously thoroughly, so that you pick up on any underlying problems with AR and QR. Also, it takes time to get used to the format of the questions properly, so be patient. Timing-wise, use Medify. It really helped to get my timings down for answers, as I had a problem initially with taking too long on QR.
Also, I would advise you not to 'cram' UKCAT practice on the weekends, but spread out the study more evenly so that you don't lose ability from week to week. Two or three days before the exam, I would suggest tapering off your practice, just so that you aren't absolutely sick of UKCAT questions on the day and you are nice and fresh.

Hope this helps! Feel free to ask any questions as I have recently gotten my UKCAT out of the way, so it's fresh in my mind.

Firstly, you sound very stressed for someone whose UKCAT is a few weeks away, chill out Try taking your time doing each and every question correctly for QR, then work on building up speed over the next 2 weeks. Tbh, I thought the questions I got for QR on the real thing were waaay easier than the mocks, so don't worry too much. If you do enough practice and are patient with yourself you'll be absolutely fine!

For analysing the graphs, pick out the key bits of data that you are likely to be asked about such as what different colours represent or percentage changes etc. One quick tip, get used to the number pad on your computer, it helps speed you up in the exam.

i went into the exam last year blind folded with no revision. i got band one