Some folks say that King for some reason alternates by writing a good book, then a shitty one, then another good book, and so on.
I don't care who you are, but you do not write 300 pages about a woman trapped in a bed. And then flavor it with some spooky spices. J-F-C.
I think this was King's attempt at writing something coherent about sex and sexuality because for some reason this territory seems to be like outer space to him. OMG - a father gets a boner around his prepubescent daughter! That can never happen to anyone normal! Burn, pedo, burn!
But seriously King, just see a sex counselor, even as a joke, and see if there really could be something that's making the whole sex issue that hard on you (no pun intended)?