I do not believe for one minute that he has sold some of your stuff or tossed it away. This is a "power/control" play. He is like a spoiled brat who wants the toys and is not willing to share. If, at all possible, don't ask about them again. If he says something, try saying, "That's okay. I am done asking and will try to find items to replace them myself". Sometimes, when you do the opposite, you will get what you actually want or need to hear.
You are a dealing with a child and until he wakes up, he's going to have selfish moments like this. They all want to control everything including the grass growing in the yard (if they could).
BTW, you are spot on...he does know that once you have your belongings that will be the end and the apron strings will be cut. It's all about holding on by a thread for them. They don't want you to move on and yet, they don't want you in their lives.
Breathe! I know you want your belongings, but please try not to ask for them again for a while. The less you look like you want/need them, the more he will see that he is losing that one last control issue over you.
