Well that explains why you went for the N2 tests.
If kanji is the main problem, as long as you have time, you can study more kanji words than those Wanikani offers with Torii (Wanikani Mode) or Hinekidori’s Anki 10k deck (you can find it in the forums). You may already know a lot of them so it would be just a matter of connecting words you know with the kanji.
Anyway, nice to have you on the race!