All of the hints throughout the story indicate that Skylar has a mental health issue. Might be PTSD-related, or it could be in the vein of anxiety or bipolar. The way his sister was freaking out about him acting like that "again" suggests that he was in a bad way before. I don't think Skylar is entirely stable, hence the way he was losing his mind and sobbing hysterically later on, having not taken his meds for a while. There's a chance he's had a suicide attempt or hospital stay in the past, based on what's coming out here and there.
When his mom discovers that he hasn't been taking his medicine, she panics, like at the beginning. I highly doubt the pills have to do with his sexuality (and if they did, they're magical pills that don't exist in this world, and they're also not working, since he likes Chan-il), but they're probably to keep his mania or other trauma-behavior in check. I'm guessing the fact that he's starting to have all of these issues is because he hasn't been taking his medication. Maybe it makes him feel a little cloudy or something. Psych meds can have frustrating side effects, but it's often worse to stop treatment altogether.
honestly i don’t even know how the author is gonna flip this around and make a romance out of this if there even is one. they’re relationships is already fucked up beyond repair.
also i forgot if it was told or not what those pills that skylar had was for, does anyone know??