I didn't mean to upset the original poster. Besides, there are posts in this thread which are far more negative (and self-defeatist) than mine. There are also many which go off on an irrelevant tangent.
There is nothing wrong with being a virgin, true, but that is irrelevant to this thread. The OP does in fact want a partner, is lonely, frustrated and at 43 I think it's about time we started giving him some useful advice before it's too late? Wake up and smell the coffee guys.
Skimming through this thread confirms my suspicions that there is more at play here than social anxiety. Probably the number one reason for virginity is poor social skills, closely followed by body issues. Seems the OP is working on weight issues... good. You need to address the core issues which effect your self esteem. For me it was acne scarring... couldn't look people in the eye. It's still a work in progress and there are no quick fixes, but you can't wait for things to be "perfect".
Looks like the OP had a golden opportunity recently with a single mother. Well... invite her out, make your intentions known early on. Women are people too and enjoy sex. Flirt, compliment her, make her feel special. Just see where it goes. If it doesn't lead anywhere then it's no big deal. You don't want to marry the first woman you sleep with anyway.
This thread has been going on since 2014 for christs sake. I know personal development is slow, but OP is a lot older than me and he needs to get this monkey off his back.