Aside from the real solutions provided by just about anyone here, I have a quick and dirty crutch to help you cope in the beginning.

Put a lock on your door, a good one. Close it. Now you are alone in the room. You are safe. There is a lock on the door which only you control. You can get out but no one can get in. Safe.

This feeling of safety and control will probably help.

I'm an aged Hikikomori and this is how I sleep. The world has tormented me enough my friend. There's a good lock on my strong door and my razor sharp Wakizashi sword is in reach.

I sleep like a baby.