I can't seem to learn my new TL despite having learnt two other languages and reaching C1 level in both.

If you can't use the grammar, you don't know the grammar. Nobody will ask you to conjugate a verb, they'll demand a correctly formed phrase. It sounds as if the "honeymoon"-phase is over and the real work starts. It will take a lot of effort, but eventually you'll reach B1-B2 and making progress feels easier albeit slower. Korean is a true foreign language for you, and I wish you luck while your perservation will make the difference between succeeding and failing. You. Can. Do. It!

It’s widely understood that proficiency in Korean coming from European languages is a much more ambitious goal than learning any European language. You probably should plan for each milestone to take at least twice as long. If you’re finding things are taking longer than that by a lot, maybe there are changes worth making to your approach.

Korean is on the opposite side of the spectrum with English and German. Everything you learning will probably take 10 times the effort. Don't use the same strategies that you used learning English and German.

A year isn't very long, maybe give it more time? Even though I understand your disappointment.

Perhaps you'd need to focus on drilling a limited set of phrases so they become second nature. Maybe by watching a single movie over and over again or something? Like kids do when they learn by reading the same books or, nowadays, watching the same cartoons over and over again.

Do you think there might also be a motivational issue? How intrinsically motivated are you to learn Korean? Is it just for the sake of passing a university class?

Have you taken into account that Korean is very different from your other languages? By that I mean English and German are related languages with similar cultures. Korean is very different from either. It may be taking you longer to adapt to the very different language.

You haven't tried reading, right? I find it very hard to retain Chinese when it's spoken, but it's easy when I'm reading a story. If there are no beginner-level graded readers available then you can try generating them with ChatGPT or Claude - I'd definitely use a paid model and get some output checked by a native speaker, though. You can then read with Kimchi Reader, which looks really nice and very similar to the tools I use for Mandarin. You should try to have a very good grasp of the phonology before you start. 

You can combine this with intensive listening or repeated listening of beginner comprehensible input videos. I think you can find a reasonable number of these on youtube. By intensive listening I mean stopping and rewinding every time you miss something until it clicks, and looking at a transcript if you really can't get it. By repeated listening I mean looping some content over and over - you should find more and more words popping in on each loop. Both of these techniques have worked well for me.

Did you actually do grammar study when you were learning German and English? 'I studied all the grammar but I can't speak or understand' is a very common complain from people who aren't getting comprehensible input.

Sounds like you need a lot more listening practice so that your brain starts building a model of Korean as a language instead of "noise".

You could try watching comprehensible input channels in Korean. These will be learner-aimed videos with naturally spoken Korean but scaled to the beginner level. These videos will be easier to understand, so your brain will start linking meaning to the sounds of Korean. It's better to use learner-aimed videos early on versus native media, which will be pretty overwhelming.

You can check this page for resources.

And read about my experience learning Thai this way here .

Lol I couldn’t make heads or tails of Korean. Thank god I don’t have professional ambitions with it. I really believe we have natural inclinations in this world

I have the same Problem with arabic. It is my fourth language and i make extremely slow progress. I think it is because it is way different than the other 3 languages i speak.

First, Korean comes from a very different language family from English and German (and based on your success with these, from your native language too). The biggest thing to note is the massive cultural switch.

I'd recommend you start learning about Korean culture, history, etymology, celebrities, daily life, mindsets, etc. etc.

Then you can start interacting with the culture and the language with an existing frame of reference, rather than trying to build the structure in your brain from only language lessons.

Once you've got this stuff figured out, the language will have enough context for your brain to accept it as a valid real thing.

At the point where you have enough context to accept the language, then do all the normal stuff; reading, youtube, shows, conversations, etc. BUT BUT BUT do not learn Korean the same way you learned English and German. These languages are too different and using Germanic family methods on non-germanic families will inhibit your growth.

The main thing I can say is that Asian cultures as a whole tend to be much more holistic/long-term/big picture in their mindset, culture, values, and beliefs. So lots of things are just crammed together in massive amounts of information that shock our western brains. The Western cultures tend to separate & categorize everything where Eastern cultures don't. Basically you need entirely new language learning processes for learning Korean. Good luck!

Try learning a basic sentence structure and trying to make as many different sentences as possible with that one sentence structure. For example in Japanese, you can say a lot with just (noun) は (description) です.

It just happens with some languages, and you have put in a lot of practice to get better. For me, it's like this in Irish, I've been taught the language for 10 years now, yet I still barely realise it's real a language when reading it

Maybe you don't like the language or are not interested in Korean culture.

Sometimes you just don't click with a language and there's nothing you can do about it, especially a language as foreign as Korean. I have the same problem with Korean btw, I forget everything as soon as I learn about it and even though I should have as an easy time with it as a Japanese speaker I just can't. I had a similar issue with spoken Chinese, reading is easy enough but even with short sentences made for beginners I could not register it. It happens and unfortunately effort isn't the way out. 

I would suggest either switching majors. You can manage to get by and graduate on effort alone, but honestly it's embarrassing to say you majored in Korean and don't speak a lick of it (as happened to many of my Asian language major colleagues). 

No matter what I do, I can't seem to keep up with my courses and barely pass my language classes. Unlike with German and English, when listening to Korean or even attempting to speak Korean, my brain doesn't seem to realise that it's a real language and doesn't pick up on any grammars, only a few words here and there

interesting. It must be because Korean is a distant language to Hungarian, English and German.

Picking words here and there is good enough, that's what happens with listening to Mandarin to me too and I don't sweat it because I know I'm improving.

But when I'm looking at a text-book, I know I know the grammar, but when I try to use it, it just vanishes.

You found out the difference between learning and acquisition. Studying grammar is completely useless.

What I'd suggest would be to learn Korean using Automatic Language Growth, but keep in mind you already damaged yourself with speaking, paying attention to language, writing and studying it, before creating a solid foundation, so you can forget native-level in Korean.

but it's like my brain has decided to completely reject everything

That would be great actually, it would mean you haven't created too much interference.