Not your fault at all. He’s a jerk. He also sounds like a typical narcissist husband who has isolated you. Do you have any family who will help you? If not, maybe try calling a crisis line to get advice. My husband pulled something similar after 20 years & I feel you with the stomach flips. I know it’s awful to find out the one person who vowed to be faithful who you trusted one-hundred percent breaks your heart. It takes time, but it will be okay.