Self Study 5 (or 7) further mathematics modules

I'm currently taking Mathematics, FM, Physics & Chemistry at my sixth form. All my teachers comment that I'm falling behind in expectations of As (I'm studying AS atm). Last year I was the highest achiever in my school receiving 8A*s & 2As. Now I'm getting Bs & Cs. I was thinking of dropping FM at school & self teaching it in the extra 3 free periods per week + 2-3h revision at home. Is this manageable bearing in mind I take in information quite depthfully & have M1,D1,FP2,M2 & D2 remaining. I'd ideally like to do them all next year. This I think would leave me more time outside of school to study Physics & Chemistry (and Mathematics which I find pretty straightforward).

I guess so, my slight worry is that you will find it slightly difficult to actually benefit from it but if you can study from home or properly in your free periods then it might not be a bad thing, even though homework is part of studying and learning, it can be difficult to keep on top of homework and out of trouble...

I actually studied Maths, Physics and Chem in Y13 and studied AS + A2 FM in my own time, it's defo possible, a bit time consuming but possible. It helps to study stats modules as well I did S2-S4, M1 and D1 in Year 13.

Thanks for your reply, it was rather helpful. Can I ask what grades you eventually got for both the FM subjects & Physics/Chem/Maths? Also, if you can remember, how much time did you spend studying for AS&A2 FM per week & over what time-period?
Thanks,