I found myself in a similar place a couple of years ago. My partner passed away, which is different and the same as your situation.
My advice… Run. Don’t worry about being fast. Get the Jeff Galloway run-walk-run book and just do it. You probably aren’t a running person. Cool, do it anyway.
Couple of reasons. One, it will help you with your emotional state. There’s something liberating about just focusing on your steps and your brain is able to organize and pack stuff away. Two, it will make a real difference in your physical condition, which also helps the mind.
Get established and when you’re ready make a goal to do a 5k or something. If you want to, you can go from watching TV to a 5k in 2-3 months. When you do that, usually those events are organized by a running club. Go to some of their events or practice runs, do an meetup or two. When you’re ready, you’ll find a bunch of people not unlike yourself.
You are 38, getting out of a decades long relationship, and you’re introspective enough to post this post. It doesn’t feel like it now , but when it’s time, you are a hot commodity for future partners.
Getting started is easy. Get two pairs of good socks and good running shoes. Then go.
Good luck, whatever you do!
+1 to running. If you run consistently, you'll learn to believe in your body as something that naturally improves if you train it well, and that belief will cross over to your mind and heart.
+2 for running. Running can become a nice little exercise and data collecting obsession.