Hello,

Hope you are doing great.

Answering to your question, you don't need to stress more about it because, the marks will be allotted based on the process/method you have followed. Even if your answer is wrong but the process you choose was right even though you won't get full marks you'll be able to get marks for whatever you have written and another way to increase marks if you are not satisfied with the marks you got you can write improvements and get good marks.

Hope this helps!!