I have a large crack between my living and dining area going across and I would like to know how to hide it.
I would just fix it. If it is a wide crack you may need to tape it first. then spackle. Search repairing a cracked ceiling. It is better to do it right the first time. Good Luck! It is not hard to repair.
This article may help: https://www.wikihow.com/Fix-Ceiling-Cracks
To fix your 'real problem', first find out what caused the ceiling to crack. It sounds like a foundation problem. Without fixing the cause first it will just continue to crack regardless how you can temperately fix it.