Just wanted to add my support and say that I am in a very similar situation.
16 year old son, anxiety and I suspect, depression, spent the last 6 months of his GCSE year at home being tutored by me. He did go to his exams but no interest whatsoever, so didn't pass anything at all. Got a place in a college but left after the first day, saying he just couldn't face going again. Found a place for him at a small training provider, so he could resit but again, just couldn't face it. I chased CAHMS regarding a referral that was made months ago and we finally had a Zoom meeting with them. Their initial opinion, was there maybe some ASD traits which are causing the anxiety etc but we now have to wait for a official assessment. After advice on here, I have applied for an EHCP but have yet to hear anything.
He has now said he has no interest of going into any further education at all, during the CAHMS meeting and whilst speaking to staff at the college, it seems there was more bullying when he was at school then we were aware of, we knew of a couple of instances but it seems to have really affected him.
He was referred for CBT by the GP in January and have yet to hear anything and the GP now wont help until CAHMS carry out their assessment.
He stays in his bedroom most of the time, sleeping. Doesn't really engage with us or have an interest in anything.
He got himself so worked up about the colleges in the last few weeks, it's like he has burnt out. We were trying to be encouraging, taking him the the meetings and looking at the courses but it seems, he just isn't in the right space and it seems to have made him feel worse.
He now says he just wants to find a job, even part time, because he can't face any educational environment.
As you said, I don't really know what else to do now. I'm trying to just be there for him at the moment.