Hi there, we don't share the same subjects so I can't really give you specific advice for those subjects. :/ But I definitely had the same problem when year 11 first started, felt so overwhelmed to the point my mental health suffered for quite a bit... it's better now but I still freak out from time to time. Even though these tips are SO generic, they have helped me personally:
Talk to someone about it: Honestly, we are all in the same boat; every one of us is stressed (or will be, especially leading up to the assessment blocks). Whether it's family or friends or classmates, it's crucial to have a support system to help you endure your last year. If there is no one you can speak to, write down your emotions onto a journal or you can PM me.
Prioritise: It is physically impossible to study everything! You have to decide which tasks are important and urgent. Consider the subject, due date and whether it is actually beneficial to you. Sometimes, teachers can set unnecessary homework and you could be better off writing your study notes. What are your weaknesses? Focus on those to improve!
Be strategic!
Break down your homework into mini tasks: Yes, technically it's the same amount of workload but when tasks are broken down into small bits, it becomes less overwhelming and therefore easier to complete. For example, instead of trying to finish an entire math exercise in one night, break it down into maybe 5-10 questions each study block! So in your to do list, simply write "Finish 10 questions of this exercise" and "Finish the remaining questions" rather than "Entire exercise blah blah blah". Seems easier to manage right? Another advantage of this is in the event you couldn't finish your homework on time, you would have at least made progress!
I actually pulled this off in year 11 3U: Further Trig was one of my weakest topics at the time. I attempted to finish the entire exercise in one night but realised I was losing LOTS of time to finish other homework. So, I aimed to finish at least 5-10 questions every school night. That way, I gave myself time to focus on my other subjects but I made progress in my math homework at the same time!
It is crucial to embrace this tip especially when you have assignments or major projects. Finishing small chunks of the assignment everyday is better than finishing the entire assignment in the night before it's due. Same with studying for exams.
Reward yourself: You are more likely to feel exhausted if you don't take breaks and reward yourself. Study in 45-50 min blocks and take 5mins breaks in between! During those breaks, make sure to go outside your study room so your brain knows it is a break. Drink water as well! Try not to take one hour breaks which I am guilty of doing on weekends HAHAH.
Another important thing is to reward yourself after finishing tasks. You finished that English essay draft? Watch one episode of a TV show! Finished that daunting math exercise for homework? Go watch another episode! Give yourself incentives so you have something to look forward to when you are finished for the night.
You worked hard all day, so you definitely deserve to have a reward.
Good luck and look after yourself!