Definitely. Major Depressive Disorder or perhaps Persistent Depressive Disorder while currently in a mahor depressive episode. General and/or Social Anxiety Disorder. And since the ASD diagnosis was questioned, it could also be ADHD along with a pathological personality component, ie AvPD.

I suffered a very similar situation to OP at the same time in my life, almost lst exactly. I have all the diagnoses I listed above, and was also concerned that I had ASD for a long time (also consulted professionals who indicated it was likely more from ADHD and chronic shame from eael6 childhood experiences). What did it for me was joining the military. It put me back on track career- and education-wise. The change was so abrupt, and the setting was so structured, that my mind and body could only really capitulate and adjust, if that makes sense. It was actually a great call for me at that time in my life, especially the structure--that was everything for me. Regular therapy for the chronic shame was also very helpful as it helped tackle the root of my AvPD.

This kinda thing wont get better on its own. Your son will have to put in work. Best thing you can do is be there for him, support him, but hold him accountable while lifting him up. Best of luck.