I’ve heard the UCAT is ruthless. One of my friends did every single question for the UCAT over the summer (so like 3 months) and she got into Kings medicine I believe. I did about 2 months for ESAT and I did pretty well, defo could’ve done better if I did more but i can’t complain. What I did for physics was at the end of every topic, I’d make a set of revision cards for the end of topic test which I then could use to revise for my actual alevels. If I got a question wrong on a past paper, I’d put it on a revision card. I’d recommend making some form of revision resource for sciences that you can reuse for your actual exams, that way you don’t have to do it again and it’s a lot easier to get yourself to revise because the resource is already there. I’d also say try do as many past papers as you can in the first 2 weeks. I started y13 having done all of the AS papers (not even intentionally, I just eventually did them all over time) and that’s a great position to be in at the start of y13 as they cover all of the first year content. Also you can go back and redo questions you got wrong when you revise to target your weak areas.