Switching to A-level Further Maths

i’m taking psychology a-level (alongside biology, chemistry and maths) but i’m finding it a bit bland — despite the fact that i found the course outline quite interesting — and i’m realising that i might just be more hardwired for science. i’ve never considered further maths as a subject choice as i always regarded it as too difficult (i’m not amazingly wonderful at maths, but i do enjoy it to an extent) and i’ve been wondering that maybe FM would have been a better option for me than psychology. the thing is, it’s near the october half-term now and so they will have covered a considerable amount of content.

i was thinking that, if i taught myself everything they’ve covered so far (it’s still somewhat early stages so hopefully this won’t be too difficult?), my school might let me switch. can anyone who takes further maths tell me a bit about the subject and how i can go about self-teaching the content that’s been done so far? is the start of the course (i.e. the first half term) similar to pure or is there a lot of new material? would you recommend that i switch for this reason alone? i don’t want to go to any teachers until i’m certain.

any input from current year 12s and also year 13s would be greatly appreciated