The most important truth you need to know is that God is even more concerned about your situation than you are and the reason is because He loves you. May you turn to Christ and discover His love and strength during this very hard time.
However, you shouldn't take upon yourself all the blame for what's happened. Your husband is trying to put it all on you but he alone is responsible for his actions, and what he has done is wrong in the eyes of God. One of the Ten Commandments states, "You shall not commit adultery" (Exodus 20:14). Could anything be clearer?
Listen: In God's eyes, you aren't dirt, and you aren't worthless. If you were, would He have sent His only Son into the world to die for you? Would He want you to be with Him in heaven forever? Your feelings are understandable but they also are wrong. Others may betray us but God never will, because He loves us far more than we can ever imagine. God's promise is for you: "I have loved you with an everlasting love" (Jeremiah 31:3).
Only God knows the future, and only He knows whether or not your husband will come to his senses and repent of what he's doing. But pray for him in spite of the hurt he's caused you, for only God can change his heart and open his eyes to the truth.