I think you should definitely try to join one of the (several) bookclubs run here in the forums, the Absolute beginners book club would probably be at a challenging, yet comfortable level for you! I find that reading with a community where you can ask your questions and discuss the sotry really helps
Alternatively, for content, maybe watch (easier?) anime with japanese subs, or podcasts for japanese language learners.
For N5-N4 level textbooks: I went with Genki (I/II) and don’t regret it
Ps. another good resource: https://learnnatively.com , which grades books/manga/novels based on their difficulty level. It would help you find material which are easier to read.