To be clear, there's a lot more to God in the Old Testament than anger, even in those instances. There's grief, especially in the flood, and in the case of Adam and Eve, God provided for their nakedness with better clothes then they had made.

To say nothing of the promise and provision provided to nations throughout the Old Testament, the grace given to non-Israelites by keeping them from accidentally violating the marriages of Abram and Issac when both men lied about their wives out of fear.

Remembering only the anger of God in the Old Testament is a common, but incomplete reading. There is also grace there.