A book of poetry will be always unfinished, words are butterflies that fly away and bounce back.
A book of prose should bring you to a level of hate, rejection, nausea.
It all depends: some will just feel that it is over, others will feed a continuous grudge, they will reject it, they will despise it.
Theoretically one never finishes anything, but there will be the day that you will know that the relationship with that novel is over.
What is left is just memory.
Once an actor finishes a movie he needs some time to put asleep the character.
I guess you will need some time to wean.
But soon your book will be over and you will get over.