HARD CHEMISTRY EXAM QUESTIONS PLZ (AS Level) and bio too ig

Heyyy guyss, I don't know if this is absurd but I need help in finding truly challenging exam questions to practice for my chemistry end of year exams. I have already done all the chemistry past papers and most of bio from 2015-2020. but I ended up getting a D grade for both. For resit I want to improve to atleast get a C and/or above. The questions that I am doing are now currently from physicsandmathstutor. but I was wondering if there is specifically a place where I can get these hard and challenging exam questions, especially *PRACTICAL* based ones. Because I remember not being able to answer practical related questions... any other advice on how I should revise is welcome too

Try doing the old specification ones and topic questions too from PMT. Test yourself 24/7, I think you just need to familiarize yourself more in order to feel confident, I don't know any other websites tbh, but you have to watch ALLERYCHEMISTRYTUTOR videos that man is a legend, he literally saved me. There is chemguide.org? I never found it useful tho.
For Practicals you should mainly input your entire focus on standard solutions, titrations, simple distilllation, flame tests and combustion questions and then you'll be fine (THEY ALWAYS ASK SOMETHING TO DO WITH APPARATUS) so you just need to know the steps by heart