Fear of further maths

Need to choose subjects ASAP
I'm sorry I've posted previously about this but change of heart and attitude.
I don't know if I can do further maths or not im scared.
Okay gcse maths is easy. Hmm ocr fmsq? (its like rhis qualifaction which introduces us to a level maths)
We started differentiation n in class I hardly stood what was going on.
I spent and hour at home learning and progressing through practise qs to exam practise until I was confident. Now I liek the topic etc. However we learnt something new today and I followed the same procedure and now I understood it.
This is seriously making me doubt my math capabilities. After having just transitioned to set 1 in a math devoted grammar school, set 1s seem so sure- my peers around me understand what's happening in class (for ad maths). Most can do the harder challenging qs while in class I'm doing the 'easy ones'.
My partner next to me understands everything straight away or nearly straight aaway and doesn't need to do the hour of revision/learning which I do and he's taking further maths aswell. Told him I'm considering doing it n he seemed amused.
Is my mathematical ability lacking in some sector? Will not being able to understand the teacher really hinder me?
I want to take fm cuz I'm taking maths n econ n it goes well. Also I quite like maths (after I understand it atleast) and I like days where I have to revise maths compared to other subjects.
I have no idea how good u need to be for further maths and no idea on how to tell if I can do it. I was thinking of maybe spending a day learning further math content to see how I get on? Will this be a indicator. Whatver I learn would prolly not be that hard anyways as its entry level stuff but still omg I'm scared.
I need 3 A*s (okay maybe not need but aspirations) and I can't let fm bring me down. Sure I could take another subject but fm is my first option and ahahsiwiwbbshsahwh
Any advice appreciated and if anyone has taken fm pls lmk how it is🙏🙏🙏🙏

I guess a few things, but hidden in there is - you have enough time on your a levels to do your a levels. Its not rocket science.
Its up to you, but if you get the grades on gcse maths (not further) and want to do it, dont overthink it. Personally, Id not do gcse further maths to not give yourself extra stress, and crack on with your a levels when the time comes. Concentrate on your gcses now. 1 extra gcse means zilch and saving a bit of time next year (when you dont need to) verses extra stress now when you do need the time seems kinda stupid. Ditch those bats/gcse further maths as johnny depp would say
https://www.youtube.com/watch?v=9gTqH_PxfPQ

wait i am definitely doing ocr fmsq ad maths I was deciding whether or not to do a level further maths

I realise, but you seem to be worrying about time to do gcse further maths and projecting it onto a level further maths. You will have the appropriate time to do the latter (a level) next year. If youre finding it tough to find time to do the former this year, dont bother (gcse/l2/...).

Oh okay, i'm finding further maths at gcse quite good tho it's fun n we finished gcse maths ages ago so I'm used to it. I would never want to not take it. Despite it sometimes being difficult n having to put in an extra hour or 2 I don't mind the time and I feel it really strengthens my understanding and is basically revision as well as learning. However I was just worried that if I'm having to put in 'extra' hours already for a level maths related stuff then what my situation would be at further maths unless it's normal to not understand what the teachers saying..