But, if you only want the story to follow Deku, and not pan over to Aizawa, then you would maybe start off the next chapter with another start of another day. Maybe some more days start to blur together. Deku gets more and more lifeless as each day goes on, finally giving up the slight hope his heart was clinging to for some reason. The knives on his skin become the only thing reminding him he is alive, (leading to obvious problems when he is recovering, and if he were to get a scrap or see his own blood it would send him into a horrifyong panic attack, or it could become a trigger for him). I'd say end the chapter with some form of, "and at that moment, in that so called bed, with no one around to hear him, no one around to see him, and no one around to care, Deku broke." Aka. Gives up hope.
Then later when Aizawa would rescue him, Deku would be afraid to leave. Afraid of the changes out side of his abusers home because is all he has ever known. He wouldn't be able to speak for quite a long time, as he never speaks to anyone now. It would take a while for his underdeveloped vocal chords to form words. He would have to learn a lot of words over again, and start learning the basics from kindergarten most likely.
Anyways, I think either of those would be a natural way to continue from this point, if you're stuck.
(These are just suggestions of course, no pressure!) <3
