Hello, it's great that we has decided to quit. It's a collective process where family members also play a role in rehabilitating the person back to normal life. Please consult a psychiatrist online. I can give you contacts of a few if you cannot visit one personally right now. His back ache needs to be treated as well.
Next Steps
psychiatric consultation
Health Tips
Watch out for him on the symptoms as the psychiatrist would inform you, withdrawal will have its own effects as you said.