Very interesting discussion. A lot of it sounds too familiar.
I was married for 20 years to a woman who, while challenging, I loved deeply. She was my world, my happy place. Then 12 years ago she dumped me and took the kids with her. For about 2 years I wallowed in black depression. It took that long before I could talk about it without bawling. I dreaded growing old alone without my best friend and lover. It was the only time I ever seriously considered suicide.
I eventually crawled out of the hole. My (self-employed) work situation changed for the better, and that helped a lot. Unfortunately my work opportunities started fading away about 5 years earlier than I wanted, so my finances aren't where I thought they'd be at retirement (I'm 66). And due to several things (ex-DW was an asocial introvert, I focused all my energy on her & our kids, etc) I had lost touch with nearly all my friends. I worked out of my home, and didn't attend a church, so no social interaction there. I did what I could to join groups, meet people for happy hour, etc.
Then in 2019 I got 2 cancer diagnoses, and then Covid hit. Due to immune issues I ended up hiding in my house for 2+ years. No face-to-face human interaction unless they had to stick a needle in me. 2 years of social isolation and hug deprivation didn't help my mental state.
I'm starting to come out of the Covid isolation, but I find I'm pretty "meh" about most of my life. I'm *lonely*, desperate for a loving companion, but I haven't had much luck there. (Believe me I've tried.) Most of my long-term friends have moved away. I'm trying to rebuild a social life, but 2 years of Covid isolation killed most of the tenuous social circles I built after the divorce. I've considered selling my (beautiful lakefront but too large) home and moving to an over-55 community just for the social opportunities.
I'm doing a lot to try to improve things. I've started playing pickleball at the local senior center. Good exercise, but very superficial social interaction. Same with hiking, once the weather warms up. Can't get in a plane while Covid is around (but that's getting better) so I bought a car I can road-trip and "camp" in. I'm buying an e-bike so I can join my brother on a 150-mile fundraiser ride for the Lymphoma Society this summer, and I plan to put many miles on it after that.
Maybe I need to add "see therapist" to my self-care regimen...