Changing the locks might give you some reassurance. I've had a lot of bugs lately but I think they are just coming in to escape the heat. They aren't welcome but there isn't much I can do about them.
I'm sorry you feel fear from being on your own. Do you fear being alone? It might be a good time to get to know yourself. If you know and trust yourself you will never be alone.
Keep posting. Hope things get better soon