As others have said these 3 subjects are very doable and interesting. They also don’t have a lot to do which specific content learnt in first year (cough plants cough). So even if you don’t do to well, don’t be too concerned.

For example, BCMB has very little ‘hard’ chemistry in it. While you have to memorise some structures and equations you are never expected to draw out organic mechanisms like you where in chem 2. Of course having a good grasp of chemistry still helps to understand the concepts being taught. But I’d say you can fairly well even if chemistry isn’t a strong point. Everything just about explained from scratch. As for bio, it isn’t even a pre-req for this subject!

Anatomy is definitely more route learning while physiology is really about conceptual understanding.

I’d say go for these subjects if they are what you are interested in and do not let your previous marks worry you to much.

Enjoy your break!