In this website it says the number of troops Robert had before and after the battle of Ulysses S.Grant (the battle where he seemed to go very bloody minded. In the battle Lee had left with 35,000 troops compared to the original 113,000.
This is letter from Robert e lee after the battle he became very bloody minded in. Even after he finally saw that he had lost he would refuse to return any captured Blacks after the defeat
This article says that he began to be to bloody minded even when he knew that the cause was lost. He could not admit defeat and fought to the bitter end. Even thought he failed so much he is very respected.