Where's
@The Cockney Rebel when you need him?
You came in here, and whilst there isn't the professional support that would likely help, you reached out. All the things you describe are valid, but there are many people out there who would be happy to be 'lonely', without the hustle and bustle of a busy life, kid's, partner etc.
I'm 59, and been single since my mid 40's, but I don't hanker for a partner. I'm oft reminded of the
"Everybody's Free (To Wear Sunscreen)" song.
Start off simple, ask yourself what things you actually enjoy doing. It could be as simple as watching a tv series, coming onto Mac rumours and participating, learning a new piece of software, signing up for an investopedia account and playing with their virtual trading app, or as others have alluded to, join a sports club, a mens shed, trying out tennis or golf, or perhaps Tai chi, which surprisingly is quite social.
If you think you are alone, and your problems are unique, you are so wrong. We all have issues, and what makes you braver and smarter than most, is you have opened up. The morgues are full of people who don't.
I love the saying
"Whether you think you can, or you think you can't—you're right"