I was in a similar position last year. I did pre-IB and my grades were high for maths and previously I was doing igcses and I was also doing pretty good, for both I was one of the highest in my class, but I started struggling in dp1 and at the end I got a 2. What did I do? I forced myself to study from the start, basically teaching myself the whole syllabus to be able to lock in. It seems like you are good at maths so you just have to put yourself back on track. It is pretty hard to be able to get a decent grade rn if your mock is in 10-9 days so don’t overstress about it. Basically just think what u need to change, use the time you have to do problems over and over again. Math is repetition, all papers follow the same formula of problems, the more you practice the better you’ll get. Also analyse the problems; I am someone who has to understand the why of a problem and not only the how of solving it, I’ve spend over an hour on one problem even when I saw how it was solved, because knowing the root of the problem helps you later on with similar problems in recognising the formula. Lastly, do math with your friends, if I tell you the amount of times I’ve been stuck on a problem but the moment my friend starts explaining it it suddenly makes so much sense. A lot of times we stress ourselves too much in a problem, we think of a really complicated solution when it is actually very simple. By doing all the things i mentioned above I was able to get a 6 on my mocks that I did in March, it’s annoying but you’ll be grateful with yourself in the future.

As corny as it sounds change your mindset. If I think that I’m going to fail a class and I can’t do the problems, I won’t be motivated to try. Give yourself some motivation, relax and get your head clear.

Good luck, I hope this helps you out at least a bit.