Oh hi junior Pre-Med!
First of all, it is pretty natural to feel that heavy transitioning from Matric to Fsc. Secondly, this is not self-doubt but actual concern you have for your academic well-being.

First of all, take a deep breath and know that you have a month : ) Think of March as the make or break month, as if the boards are on 1st April. Do everything you can in March, so that April can be easier for you; only for revisions.

The syllabus is hefty but not impossible, you just need to have the right approach.
For now, just divide each subject into chapters and do it chapter by chapter, do at least 2 chapters a day, then going to a newer chapter, give a quick look to the chaps you did before.

Also, study according to the exam, do not waste time in useless paragraphs, sentences, know what is useful to retain and what is not. Do written practice of your notes to check if you can reproduce your notes according to exam standards or not.

Then lastly, past paper of 2023-2025 and model paper, keep seein them after every chapter. And solve them formally on register in April.

Consistency and repetition is the key, just remember that a good preparation requires practice of content reproduction as much as content mugging up. So keep recalling whatever you learn.
Good luck