This is just a rollicking good yarn, no two ways about it. It will make you chortle like a drunken buffoon, and sob like a forlorn sissy. And sob you will, even though you read it long ago (before you developed emotions, apparently) and have seen the movie multiple times. It is that grievous. (See how I'm using the second person to distance myself a little from forlorn sissies?) You were just looking for a little escapism, and here you find yourself reading something on a par with King Lear, or the book of Job. Mitchell creates unforgettable and complex characters; she writes with great humor and her writing is occasionally quite good; and you just have to give her props for sheer bulk, typing this whole thing out on a Remington manual over five years and sticking with it.
If there's one thing that makes a reader uneasy, it's wondering how slippery she's being with historical truth, and if she's writing unrealistic things, should this bother you? It is fiction, after all. You need to read some history on the postwar era to find out, e.g., how many slaves - now that they were free to go - decided to stick around with their masters like Mammy, Pork, Dilcey, Peter, and Prissy do (and they wouldn't have it any other way, being bosom buddies and all). And how much the creation of the Ku Klux Klan was prompted by freed slaves raping white women. Beyond possibly being slippery with historical facts, there are passages from the omniscient narrator about negroes being like small children, or monkeys, and constant discussion of niggers, darkies, and pickaninnies, which you are not sure how to process. You might give that some more thought once you have finished weeping.