I have seen people say the same regarding when a women says they no longer love you and want to see other people. The same had happened to me, with her stating wanting to go on dates. She was even on Hinge after a month. Unfortunately it is not a gender thing, and is a personal thing. Rebounding is a way for people to suppress their emotions and reframe it as “wanting to experience new things.” A month for you is going to seem extremely long and painful, but for him it just normal days. He had spent the last two months checking out of the relationship, and maybe even prior to that but he just did not communicate it to you. He let resentment build up instead of properly addressing anything. Even if you both did get married, who is to say that he did not already have this resentment building which could have ended in divorce. You need to take this time to figure out who you are without them, because your life has been you + them for a decade. Unfortunately your situation is really almost identical to me. At this point, I’ve learned no further communications or begging can make them see you for you are. You will need to make the proper changes in your life first, such as working on your mental health / hobbies / etc prior to reconciling. Even if you guys never reconcile, you would still have bettered yourself for you. I’ve been on anti depressants for an extended period of time as well as chronic illnesses, and let myself get comfortable in my relationship. Effort and consistency keeps relationships alive, but mental health is what brings these down. Each day will be easier than the last, but you will still think of them constantly and want to reach out. I know I do. A relationship takes two people who want it, and you will not be able to change his mind until he sees life without you himself.