Control what you can control, and forget the rest. You're never going to be happy until you can learn some level of self-acceptance. You're almost 50 years old, and are exhibiting behaviors of someone who is far younger and less mature than you should be. I'm not saying it to be a dick, I'm saying it because you need to hear it. You probably have friends and family who feel the same way, but don't know how to tell you.
If you feel unlovable, or untouchable, only you can fix that. You are projecting your own insecurities on to others, and it's just a horrible and self deprecating cycle. I've been fat my whole life, and I felt the same way you did for a long time. I one day realized that I just needed to grow up and live in reality. Things weren't going to just happen to me, I had to go out and get it. So for years I worked on my feelings and maturity level. I got therapy for a little while, and it helped ALOT. I can't recommend it enough. Once I was on that echelon of emotional maturity, I was able to start actively seeking relationships. I was maybe 250-260lbs when I met my wife, but she still married me. After getting married, I gained a lot of weight a new sedentary job, and I still had some emotional work to do. But I started keto once it hit me that I was going to be a role model for kid, and really turned my health around. But there was ZERO chance I could have done that without first strengthening myself and just flat out growing the hell up lol.
I know it sounds cliché or whatever, but you legitimately need to work on yourself before you can expect to receive that level of love from someone else. Not a lot of people are going to want to be with someone who is down on themselves, and have noticeable self esteem issues. It's so exhausting, especially around your age level. Again, I'm not trying say these things to be an asshole, but it seems you need a dose of reality.
You are not alone, and everyone in this sub is supportive and are in this together with you. Get some help, work on yourself, keep up with Keto. Do these things, and before you know it, you are going to be a completely different person and some lucky guy is going to notice your bright personality, your attractive confidence, commitment to self improvement, and of course your awesome physique (brought to you by keto :P) and try to court you.
Hang in there, and seriously take a little time and figure yourself out, and do not be afraid to get some help.