My boyfriend still hallucinates while sober.

Long story short, me and my boyfriend decided to drink a little together one night. He got a little too drunk and admitted to me that after being addicted to adderall and vyvanse for two years, he still hallucinates after one year of being sober from them. It broke my heart seeing him so crushed, and when we talked about it a few days later, he admitted he was scared to tell his doctor in fear of being hospitalized. I don't blame him. But I'm looking into this to hopefully help him. At first I was thinking it was withdrawal symptoms, but it seems to have been a really long time for them to still be going. I'm starting to think he may have developed HPPD, because his hallucinations are so persistent, and if he has it I know going to a doctor may be the smartest choice. Has anyone gone through something like this or may know what to do? I know it's his battle to fight but it won't stop me from helping and supporting.