ok.
firstly, everyone's brains and skills are different. not only are you NOT stupid if you find maths hard or just flat out arent passionate about it, but you can pursue so many other areas and be successful.
if money/job security is a big deal to you then there are plenty of jobs that dont require maths, such as in areas of law and management and many more
if youre just thinking about your happiness and enjoyment i would say definitely do not force yourself to do maths if it will make you unhappy! A level is a BIG step up, and if you study a subject you already feel nervous about it could make things quite unpleasant for two years.
from the sound of things you are hard working and driven, so you may well be able to make it work, but its really not the end of the world if the idea is just too scary/unappealing.
one thing i will say, and i KNOW my experience will not be the same as everyone elses, but I found gcse maths horrible and was constantly asking to be moved down from set 2 to 3. they decided to move me up to set 1 instead and i thought they really had it in for me. i did manage to get an A which really considering how hard i found it was pretty miraculous, but most of my class got A* so it felt less special.
then for some reason, i decided to do it at A level, planning to drop it after AS (i think because of the same reason you mention, because not doing it might make me somehow feel stupid). i was sure i would fail, but for some reason i just clicked with it, and now maths is probably my favourite subject, and the one i got my highest UMS in.
so choose wisely, pay attention to your feelings and your own personal happiness, but if you DO end up studying maths A level for whatever reason, then i guess have faith in yourself and know that just because it was a struggle at gcse it doesnt mean youre doomed.
i dont want this to sound like im telling you to do maths and not pay attention to your fears, but yeah, do think carefully about this, which im sure youre already doing
good luck!