Feeling stuck. What’s your experience?

I don't know what to at this point I'm at, it all feels hopeless. I need to hear how you guys got past it or if you've ever experienced it or how you got to the point you're at right now in japanese language study/knowledge.

I've been watching anime for 10 years give or take so when I started studying Japanese at college, n5 and n4 felt like a breeze. The vocabulary was mostly familiar with few exceptions, never had problems with kanji study cause that's just my favourite part and grammar was really easy to understand. It was direct, had literal translations, it just "clicked".

Come around third year and n3 grammar and it suddenly felt like a HUGE leap?! We're using books from a different publisher so some grammar points repeat while others the book assumes we've gone past and just regularly uses them in text (ie: sentences ending with である while such a thing never appeared before, and language being a lot more casual and "free", "fluent", compared to textbook japanese I got used to). New grammar points are extremely hard for me to understand and I don't memorize then as easy as before (ie: substitutes for で such as を通じて、に際して etc. There's nuance that even tho I "understand" on paper, i can't differentiate as well in practice).

I've always had a social anxiety issue so talking, no matter the language, has been an uphill battle and japanese was no different. So so far I've really just talked in the most basic n5 sentences, more often than not replying with hai or iee.

I feel stuck from every angle. I feel like I'll never understand the new grammar from n3 and above (I know that's not true, but it all feels so impossible like never before), words have been harder to memorize as well given that they all sound so similar (going from a ありがとう which sounds so unique to 10 words containing 感 all with similar but distinct meanings), I feel like I'm extremely behind on conversation skills now that effectively 3 years had passed since I started studying and I don't know how to make the next step because it all feels so overwhelming. My study methods so far seem to be ineffective now.

Tl;dr how do you study n3 and above when it feels so much harder than previous levels and when you feel stuck. What are the best study methods? Is it really just about giving it time?
Please help? TT

by johnson_johnny