True freedom from sin will never be found keeping the law (even though the law is good), because of the gigantic gap between the demands of the law and the sinfulness of the flesh. Only the cross of Christ can bridge that gap.
Don't worry or become angry when the wicked prosper. It won't last. They will be judged and God's truth will be vindicated. Simply trust and delight in God. Commit all your ways to him as you wait for him to act. He always wins in the end.