Let's try to re-frame that. Your H was unhappy in the M, but he had various choices about how to handle that. He didn't have to choose S, he could have communicated better, he could have let you know sooner, sought help sooner etc. Those choices are about HIM.
In the meantime, you have been working on you and making incredible steps forward in your own journey. That, in and of itself, is worth celebrating!