Advice on UCAT please

Depends on what your weakness is, because with the UCAT success is pretty much all about practice. If you're unable to complete enough questions in time to get a higher score, stick to completely only timed questions. However, if you answer all of the questions but get some wrong, try to answer more untimed questions to improve your understanding, and then end your day with some timed sets.

Which section are you struggling with the most?

With AR the advice I had received was (on the questions with sets), to take longer on the first question to determine the correct trend, as you can then answer the next questions in the set within 2-3 seconds. If you were to guess for each question, this could take significantly longer.
I agree that the timing for VR is horrible. I'm not sure how you go about solving the questions, but I was told to answer the first 8 texts carefully and then try my best to hurry up for the last 4. Also, it's better to dedicate a couple more seconds to read the text carefully the first time rather than have to skim it for every question, because you're going to be re-reading the same points and wasting your time overall.
For QR, make sure you're practising with the calculator on the site and not a physical one, as that can cause you to lose a lot of time during the real exam, other than that QR is all about practice, as the style/format of questions is quite repetitive.
Also, I cannot stress enough how helpful flagging questions can be. If you can't figure out how to solve a question and you start to stress about the time, flag it and come back at the end. Get all of the simpler questions out of the way, so that you'll have the guaranteed points.

This is just the advice that helped me, I'm sure as you keep practising you'll find what works for you as well. Give it your all for the next 10 days and I'm sure you'll have nothing to worry about. Good luck!!

I have been doing practice questions timed and untimed for the last 3 weeks.
This week I started doing mocks- the first one I got 2510, the second one 2380, and the third one today 2230. So my score keeps decreasing for some reason.
My test is in 10 days, do you think there is hope for me? I am aiming for like 2700+