The best way to help your husband get over his mistress is to provide support and understanding. You can offer to talk to him about his feelings, listen to him about what’s going on, and reassure him that you love him and want the best for him. You could also try suggesting ways that he could improve his relationship with you, such as spending more time together or communicating more honestly. Ultimately, it will take a lot of effort and support from both of you for your husband to finally get over his mistress. But with a little empathy and patience, it can be done.