I think anxiety attacks CAN be anger attacks for men. I don't think that's b.s.
He may need an AD AND an anti-anxiety, but you can't make him stop ordering meds off the internet or wherever. He may be right about his pilot's license, which provides an awful incentive for this self-doctoring. His admitting he needs psych help but will only do it himself in secret is very controllign approach to his whole mental health issue.
The vicodin stuff, if stated frequency is true, is worrisome. Once again, is it true? And is he mixing it with whatever anti-anxiety pills he's getting off the internet?
I don't know what to say about OW. I would ask IC about this drug issue. You could try to bring up OW topic in a calm way another day and say you are just ready for the truth, no matter what it is and hope you hear the full extent and gauge whether or not it sounds true. Remind him the separation agreement is signed, what does it matter? You just want to know so you can move forward. ?