Hey, I have made some room for PMs, so if you want to send a private message, go ahead
As for your question, I didn't really use a textbook for 4U, the only textbook I had was the Fitzpatrick one but that's because the school told me to buy it. I never used it after the middle of Complex Numbers because its pretty awful
For studying maths I would go on marathons, look at last questions on past papers, go on problem solving sites etc. My method was very unorthodox, if you don't want to aim for a state rank, I suggest not taking my method and asking someone from a high selective school about what they did.