My husband wants to leave me

Hi my husband is very depressed right now.his job is no going well and he told me he wants a new life. Then he stared accusing me of not getting pregnant or ready to have babies. I got to admit it is my fault because I promised him to lose weight if he had the reverse vasectomy done. He got it done but I didn't keep my promise. Just today he told me he wants babies now and he doesn't believe in me changing. He ask me for time alone to think. What can I do to get another chance with him?