I’m in a similar situation as your son. I graduated the same time your son did, but I wasn’t diagnosed with ADHD until a few months ago. I didn’t do much the summer before I started college because I needed to mentally prepare for it. My mom got mad at me for watching too much Netflix, and not getting a job. I wasn’t trying to be lazy, I just couldn’t find the motivation to do the things she wanted me to do. This could be the reason he’s spending so much time in his room. I also went to a 4-year college out of state, and my grades weren’t that good last semester, I failed a class. The classes I did the worst in were the ones I didn’t like. I also let some people that were spontaneous and fun to be around but not necessarily concerned with doing well distract me. I’m doing much better this semester and I’m at the same college but taking classes I’m more interested in. The point is that he needs to be doing things he enjoys in order to do well at them. He might just be recharging when he’s in his room. I know I need lots of alone time or I start getting frustrated at the people around me for no reason. Otherwise, it might be like me with Netflix, I don’t realize how much time I’m spending on it and I can go all day with it only feeling like an hour. Socializing is really hard with ADHD, be patient with that. Does he try? Also it sounds like you got it under control but he might have forgot about the meds while he was out of state. I know I forget to do things all the time, even if they’re already a habit or I wrote a note to do it, or he might not like the way the meds make him feel. They can come with some really bad side effects.