My husband (40m) started using the gym and now he wants to divorce me (40f)

I just need some advice on the next steps I should take as I'm still overwhelmed by the news. My husband started working out last summer. It all started when we went to the beach and he didn't like how he looked in the T-shirt so he decided to start working out. He wanted us to start together but I have never been a fan of going to the gym, it makes me feel uncomfortable and I love walking and hiking. <br><br>&#x200B;<br><br>He got a personal trainer and he was going 4 times a week. He was also receiving nutrition plans as well. I didn't think anything of it but my sister said it's a little weird for him to get a PT for such a simple thing as weight loss. I didn't think much of it and honestly, I wanted to support him.<br><br>&#x200B;<br><br>At the beginning of this year, he started going to the gym every day, he completely cut out booze and started eating way more healthy. He looked amazing and I was so proud of him. Our sex life was never great, as he has always had ED but after he started going to the gym, he was very into sex and wanted to do it all the time. He started exploring new things in sex, which I wasn't a huge fan of as I'm a vanilla type of gal but I wanted to make him happy.<br><br>&#x200B;<br><br>Last weekend he told me he has been feeling unhappy in our marriage for a while but the gym helped him to see that we should divorce. He said he's been feeling unhappy for a year but the gym helped him to find confidence and energy and he feels like he can do it now. He told me he's been chatting to a girl from the gym for a few months and she's a friend but he is planning on exploring things with her.<br><br>&#x200B;<br><br>I was heartbroken and I still can't believe it. We have no fights or any issues in our marriage and I did everything for him. I always supported him in everything he does and he did the same for me. I have no idea where it went so wrong and what I can do to save our marriage. I don't know what to do.<br><br>&#x200B;<br><br>He is still living with me and he told me he is going to stay with his friend until he finds a new place. He said we will share the house until we get a divorce and sell the house.<br><br>&#x200B;<br><br>What should I do next?