New here - post 16 education help

Hi I'm new . My son is 17 and  awaiting assessment for diagnosis.  He started college in 2018 and left after 2 terms. He restarted at 6th form but didn't actually start. We have been turned down for ehcp assessment.  We are appealing. His mental health (ocd and anxiety) are preventing him from attending mainstream further education 

My question is what other opportunities have people experienced post 16? I think he could manage online distance learning and is capable of achieving further qualifications.  He did really well in gcses. 

Thank you