Hi there, I sat the UCAT in the summer and got 3090 overall (VR 700, DM 700, QR 800 and AR 890) and band 1 sjt. It's incredible that you've started ucat prep so early, most people honestly don't do that much until the summer. I found the ucat very stressful - not something that came naturally to me and like you I worried about score fluctuations on websites etc. However I will say I used meddentry a lot a month before my exam and for me personally (of course can't speak for others) it was pretty accurate to my score on the day and I felt reflected the ucat a bit better than medify (which I used a lot too). The diagnostic mock is shorter than the real thing if I remember right so I'm not entirely sure how accurate it'll be (sorry unhelpful lol). I would say do take all mocks with a pinch of salt, there were some I did a lot worse on than others, and instead focus on the bits you need to improve on from each. Practice is definitely key, if there are certain question types you find hard I'd recommend doing untimed q's for a bit before a full 2 hour mock. But honestly you're doing so so well, I hadn't even done a full mock in April as I thought it would knock my confidence and didn't feel ready then, but in late August when i took my UCAT it was okay! keep going and if you have any questions I will try and help!