Advice needed

a But of a backstory. I have no friends at school due to a falling out with a friend group a year ago (they bullied me heavily and verbally attacked me many times) they spread false rumours about me so no one really wants to be my friend.

i had this online friends I’ll call him “F” F and I are pretty close or at-least “were?” We talked all day and had so much fun together, he himself confessed his own friend group doesn’t treat him all that well but we never touched that much about that subject. He knows I’m alone and deal with an insane amount of abandonment issues. He promised that if I ever did anything wrong that he’d talk to me, or if he wanted to end our friendship for whatever reason he’d also talk to me first and not plainly ghosting me, which I appreciated.

all and all we were pretty close, did a lot of things together like watch movies and buy books that the other recommended. However he also like me has pretty rough mental health conditions and problems, so he announced he was leaving Twitter (which is where we met and talked most of the time). It was fine by me because I 100% support people who leave apps to take care of themselves, I also had him on most of his other social media.

he ended up leaving all social media, again that’s completely valid and alright. He still has his WhatsApp on, I messaged him a few times trying to check up on him but there was no response, he posts on his WhatsApp story almost everyday and views mine, he posts about his books, football matches even real life friends. However he hasn’t replied, I kept an open mind that he might just been unwell and taking a break and still am trying to keep an open mind.

however it’s been 16 days, there’s no telling if hes well or not but he hasn’t replied or even seen any of my messages. He didn’t mention anything about wanting to distance himself from online friends and all so I’m concerned about him and what it means for our friendship. As much as I love him and support his decisions to taking breaks I am a little upset that he didn’t clarify anything to me before leaving all social media, he claimed I was his “best friend” just a few days before he left. Which struck me because if I was truly his best friend I would’ve loved even just a tiny reassurance. I’m not even sure if he replies on WhatsApp anymore but he did before his break. I’m just really scared if he’s ghosting me and is never going to come back again whilst I would respect his decision I wouldn’t say I’m hurt, just worried.

what do you think is happening? Should I calm down and reassure myself that he’s just unwell and needs time away (he never mentioned if he’s going to come back to social media) but he’s a teenage boy and I would assume he’d back at some point even if it’s in just one app. I’m really worried and I would love some input <3