Started A level this year and failing everything already...

I moved to the UK from the Netherlands a couple months ago and went straight into A levels (year 12). Initially I chose physics, math and further math but 3 weeks in I got kicked out of math and further math because I don’t have the GCSE knowledge.
Now I’m doing physics, psychology and biology. I understand near to nothing because I haven’t studied here and don’t know some of the terms they use. Also I don’t enjoy psychology or biology.
Till now I haven’t gotten anything over 50%...
At this rate I think I’m going to fail throughout the whole year and will have to repeat year 12.

Are there any other options for me? I don’t really want to repeat the year and have to redo the subjects that I don’t like.

Any advice would help

It's worth looking on the exam board websites through the specifications to see what subjects interest you. Every subject has its positives and negatives and not everyone agrees as to which subjects are the hardest. Generally, subjects are divided between Sciences (including Maths), Essay subjects, Languages and Coursework subjects.

I would suggest revising content and keeping notes and folders organised. Practice lots of questions in Physics and Biology and learn the mark scheme. Sciences are notorious for being cruel because a specific word wasn't used. A surprise common knowledge question may come up or something weird
like the anatomy of axolotls, forces of a surfboard, standard deviation or the physics paper turning into a 70% maths paper.

Psychology is a memory game and its all about the exam technique. Some topics (the Psychodynamic Approach) can be weird and others can be controversial depending on what you believe (Nature-Nurture). Flashcards and remembering things in groups of 3 can help. Most things are already in 3s like the Tripartite Model, types of conformity or parts of operant conditioning.

Generally, its a shock to UK students that there is Chemistry in Biology so I wouldn't worry about not knowing anything at first. Similar to Psychology, not many people did it at GCSE so you won't be the only one clueless. Doing past paper exam questions is the most valuable piece of revision when you've covered at least two large topics (so about after Christmas). Practice makes perfect. I know a student who had choose two new subjects after Year 12 mock exams and they still ended up with A*AA because they put in the extra effort.

I highly wouldn't recommend changing subjects after October half term but if you are, I'd suggest to do it now rather than later. Subjects can include:

English
English Language focuses on how people develop language and how children start to speak read and write. English Literature focuses on lots of books and requires you to recall lots of quotes to evaluate in the exams.

Maths
Maths is quite a demanding subjects and is split into Core, Mechanics and Statistics. Core Maths is related to quadratics, cubics, differentiation, numbers, algebra and kinematics (Motion Physics). Mechanics is sort of like Physics and Computer Science while Statistics is what everyone hates (probability).

Core Sciences
Biology consists of a unit which requires knowledge of basic organic chemistry while lots of it is fact recall and application. There is lots of waffle and you essentially just need the key points so you don't need everything in the textbook. It is one of the most content heavy subjects though, if not the most.

Chemistry is known as the hardest (apart from Further Maths) due to the large jump between GCSE and A Level. It explores physical and organic aspects of the subject. Most students hate the organic side due to the need to recall functional groups, reactions and nomenclature.

Physics covers waves, forces, motion, astrophysics, electricity, medical physics and radiation. It has lots of maths and it is suggested that maths is done along side physics. You need to recall some basic equations such as F = ma and know how to use harder equations which will be given.

All sciences have practical endorsements which is basically and assessed practical which doesn't contribute to your final grade. You just have to follow instructions and be at the practical to get a pass so its not that hard.

Languages
It require lots of vocabulary and learning. Its essentially English Literature in another language. Teachers will most definitely always speak in the language you choose unless English is needed.

Essay/Coursework/Other
Religious Studies, Sociology, Psychology, Business, Economics, Electronics, Media, Photography, PE and Politics don't require GCSE knowledge and in some cases, the specifications for GCSE and A Level won't correspond. Psychology, for example, is far too different at A Level so students who did it at GCSE essentially have little to no advantage.

Religious Studies isn't purely about religion. It includes philosophy and ethics such as abortion. There is still the religious aspect as you will learn in depth about one religion (Christianity, Judaism, Islam, Buddhism, Hinduism or Sikhism) which depends on the schools choice.

Geography and History will require a high decent GCSE equivalent grade but due to there being 4 million History topic combinations the work could be new to some people or an extension to others.

Depending on schools, Art, Tech and PE may have certain requirements from GCSE as these subjects are coursework heavy and A Level would only enhance skills rather than building them.