I have a friend I can't help worrying about. The last time I saw them, they seemed like they were in kind of a bad way, stressing over school stuff. At the end of the day, they left immediately without walking home with our usual group. Since then, they haven't been at school and I don't think they've left the house. I've tried asking if they're okay, and they told me yes, but since it was over text I wasn't entirely convinced. Haven't really had any other contact with them besides that.
Part of me thinks the right thing to do is to give them their space, let them take time away from everything for a while. But another part of me can't help but be worried, but I don't know what I can do to help. Should I even help? Am I just being paranoid?

If you think that your friend needs their space then let them have but if you want to help try sending some stuff that they like to his/her house. You can even leave a note saying that you are worried about him/her.

Heya - everyones different and every situations different too so everything i say could be either super helpful or extremely the opposite, but i have a lot of experience with bad mental health stuff, especially trying to deal with my friends going through some pretty serious stuff, and honestly i think the best thing to do is to tell them that your worried, no beating around the bush, and that if they need to they can reach out to you, but that you wont pressure them into telling you anything if theyre not comfortable - also try to keep in contact with them as much as possible, even if it's just sending them small talk kinda texts or little jokes or just telling them how your day has been - it can be really helpful to hear that kinda mundane stuff to keep feeling normal and included.

I was lucky in that i was quite close with my mates parents so if i was ever more worried than usual, i could call his mum to check if he was ok. it might just be the usual stresses of school and all that, but if it keeps going and youre still worried and havent heard anything i honestly would suggest going round to their house if you can and just asking if theyre in and if you can see them. even if all you do is say hi.

I dont know if any of that helps at all but i hope your friend is ok :) x