A cure for bipolar, depression, schizophrenia or other mental illness would be a state of recovery where no more symptoms were present and you were returned to health permanently. This is the one that is contentious in mental illness.
Typical king-size beds measure 78 inches wide, while queen mattresses are 60 inches, full beds are 54 inches and twin beds are 39 inches wide. Visit a lumber or home improvement store and request the wood to be cut the exact length to save you some time and trouble.
Purchase 2-inch-thick foam the same size as your plywood, and batting the size of your headboard plus an additional 8 inches on each side. Choose durable fabric that won't tear easily when stretched. Add 12 inches to each side of the headboard's measurements. For a 60-inch-wide queen bed, you'll need 84 inches of fabric across and 60 inches for the height of the headboard.