Take a moment and step back. What life skills is he missing? Once you have established the gaps, you can teach him the life skills he's missing. What is passionate about? Is he just fearful of being out on his own? These are conversations you can have with him. Explain to him that you aren't always going to be there and he has to be able to survive without you. This isn't about being mean and leaving him on a street corner with a backpack, it's about him being independent and taking control of his own life.