I got back in shape. You're already doing that and that is great!
I bought a motorcycle. Still have it, love it, she hates it, I'm never giving it up. It's my time now.
I got back into guitar playing. Then I put out an ad in craigslist for other middle aged musicians that had given up playing years ago. I was just planning on putting together a 3 piece band and needed a bass player and drummer. I underestimated the demand for something like this. I got 30-40 replies which turned into a regular jam session and get together. We all formed little bands here and there where we interchange people and we blanket our area for open jam/open mic nights and perform just for fun. It's an absolutely blast.
I do have to admit that I also went for lunch or coffee with members of the opposite sex. Not really dating, kept it friendly and very casual, but if I had been so inclined it definitely could have turned into dating. What that did was make me feel like a man again. That was probably the biggest confidence booster throughout the whole thing. I HIGHLY recommend it.
I bought a hybrid bicycle (trail/street). I still ride all the time and enjoy it quite a bit.
I like to rent kayaks at a local place and kayak down river. If a friend could go that was great but I went alone quite a bit. It's just you, the kayak, your paddle, and the river. The company transports you up river in a van and gets you started and then you paddle down river back to their place. They have 10 mile, 20 mile, and 50 mile trips. I LOVE it. My wife and I go now and we both love it.
That was the majority of my GAL. I really had a personal awakening when my wife crushed the core of my being. I know this for sure. My personal happiness and wonderful life will NEVER EVER AGAIN be dependent on anyone else but me. Never.