This is such a good question that I have been ruminating on it. Sin is inherently destructive so when we sin it is a self destructive act and the ultimate act of self hatred. When we fight against sin (even if we lose) that is the ultimate act of self love.

As other posts seem to confirm, the root of self hatred is sin.

Also keep in mind that Satan hates you and wants to destroy you. Self hatred is not natural. IMHO self hatred is a sign of demonic influence.