Hi!
What about calculation questions is throwing you off? Interpretation? Knowing what steps to take? Losing which values go where?
One thing I highly recommend if the long ones in particular are throwing you off is trying to be really clear and explicit in your working. E.g. rather than just n = 2.0 using n(HCl) = 2.0 mol. Having clearer working helps you stay on track and think more logically through the question as well as making it easier for someone marking you to see your working.
For questions I recommend looking at past exams in other states. Where and what years you look at will influence the content but you should find it fairly easy to find questions relevant to you - just check the syllabus or ask if you are unsure whether a question would fit in Qld.
For example, here's where you can find:
Victorian past exams (go to old exams if you want to practice things like pH, pKa etc.)
NSW past examsE.g. the 2009 Exam 2 from Victoria you should skip a couple of questions near the end but most of it is relevant including calculation questions.
Do you know how to use things like ICE / RICE tables to simplify calculations for equilibrium questions?
I hope this helps & remember that you do still have some time to learn from your mocks - lots of people will be feeling taken aback by them and you're definitely not alone