He sounds very needy, and I don't see him changing because everyone (his parents and you) cave in to his behaviour. I understand the reluctance to confront him, because it seems mean. No one really wants to be mean to someone who claims to adore you. I doubt if he's going to change, and the longer you allow this to go on, the stronger his sense of ownership will become.
I am sorry to be so blunt, but my first husband was a needy soul who became possessive and abusive once he felt he had established ownership. Those 4 years of marriage were the unhappiest of my entire life, I became a shadow of myself. I can't guarantee he will become like my ex, but he sure is making alarm bells go off in my head. You have to think long and hard about how you want to live the rest of your life. I think you will become demoralized if you try to encourage him to spread his wings, I don't think he will because there is no real incentive to change. He likes the way his world is, and all that quasi-adoration is manipulative. What will probably happen, if you continue, you will get tired of the utter frustration and give in to his hermit ways because otherwise he will exhaust you. Please don't let that happen, you seem young and that's a good thing. There really isn't any good reason to chain yourself/sacrifice your own interests for a young man who seems so content with his limited lifestyle.
I do apologize for being so negative, but there are so many more interesting people out there for you to meet. Relationships aren't sunbeams and fairy dust, but you seem to be sacrificing so much after only 11 months. Find someone who suits you better, being fond of someone won't be enough to carry you thru the actual tough times.
Good luck in the future, and I think it was very smart of you to describe your situation so accurately. I think you know what you should do, but it's never a mistake to say out-loud or write frankly about how you see the situation.