As the thread is closed, I opened a new one to say something to Hong Sien and all who might be having the same problem. However I want to first tell all no to hijack the thread to ask people to accept Jesus or Buddha etc. I think this should not be a chance to convert someone using his weakness or problem as a stepping stone.
For Hong Sien The reason is very simple, in the day you think about ghosts, spirits etc hence in the night or when you sleep, your mind is regenerating the images in your head. Like watching a movie. Hence in the day now due to the fact it is 7th Month, you are bombarded by images of paper money being burned, rituals and all things associated with 7th Month. And then you yourself keep thinking about it, making it worse.
Try to not think so much about such things, take it as just a ritual, a time in which some festivals are being carried out. And drink camomile tea before you sleep to calm your nerves.
If you decide to seek religion, seek what you are comfortable and not what others tell you. For if you beleive because others tell you to then you are not really believing.