You are not alone!
From your reply you are caring, careful, well motivated and ambitious. All very good!
But there are several little hints that you are under more pressure than is healthy for your thinking. Please ask your parents or a wise adult you trust about this. You will do much better in exams if you have a helpful, caring, support group!
My suggestion : copy out the " 8-=3(3)4/6-2 " very carefully, and check each small part of it against the question paper.
Now check the order of all the bits.
Now write what you are asked to do: 'Simplify' or 'Solve' or 'Factotorise' or 'Find x' or some such. Check you have spelled it right - like fix my mistake
I should have typed 'Factorise'
By doing this, you have built your confidence with 100% so far, and you have been taught all you need to do the rest.
In the book 'Don't you have time to think?', many of Richard Feynman's great letters to people like you and me have been collected. His main advice is "Trust the evidence, not the authority." Possibly because each of us sees things differently.
Please write again: hopefully better answers than this will appear!