Thanks for bringing your question to JustAnswer.
I would strongly recommend that you not see him until he gets better. Clearly, this is not a man who is ready for a live-in relationship. It is highly unusual for someone who has been in a relationship for 10 years to react with severe depression when asked to go to the next level.
If he is this conflicted and desperate not to discuss moving in, then the next question is if your life goals are compatible. If your eventual goal is marriage (or at least living together in a committed relationship), I would strongly recommend couples counseling once he is out of this deep depression.
If he won't agree to that, go see a therapist by yourself. You need someone to help you figure out if this man has the same plan for his life as you do. You have given ten years to this relationship, and you need to figure out how you will feel if it never goes any further than it is now--living separately.
Moving in while he is in such conflict would be a very, very bad idea. Drop the conversation completely until he's out of the depression, and then try to get him into couples counseling. He's already on medications, but he may want to have them re-evaluated--they may need to be adjusted. He also may need individual counseling as well to help him recover from his early trauma.