So…. I forgot several years worth of japanese

So Im a teen who forgot years worth of japanese ive been studying since I was 9, I have ADHD so even though I was inconsitent and made little progress i still made progress none the less however in the last 2 to 3 years I forgot pretty much alot even some katakana due to not using or studying due to a mental health crisis, depression, dissociation, psychosis etc.

I understand because I know japanese is a extremely hard language to learn I expected this to happen but its frusturating to return to square one none the less.

Okay so heres the problem, my mom forgot the screentime passwords so I cannot use any apps, so im gonna have to rely on something else, I can have apps on my laptop just onto my phone. Also I cant use anki. I heard that immersion for several hours a day while using flashcards is THE most effective way, but what resources do you recommend.

I also have a beginner japanese textbook, but idk how many pages I should do a day.

and how can i prevent forgetting this time around

tldr any NOT mobile resources do yall recommend , how much do you think I should learn a day, and how can I prevent forgetting this time around

by iichisai