Life often throws us curveballs.
I am sorry you feel dispondent....but want to tell you that you should not lose hope!
I am 42. I've had two bf's in the last three years. One at 38 and the one I have now, at 41. I want to stay with this last one...just showing you that getting a bf at our age is more than possible and it happens often.
I imagine living where you live makes it harder. I live in a metropolitian coastal area where it's very OK to be single...even if you are much older. I mean, I am sure there are some who are judgemental...but in my crowd, they generally are not.
Is it possible to move?
If not, set an example! Be a wonderful, vivacious, LOVING, friendly, HAPPY single woman who is 40! Trancend the cultural ideas/impressions and be a pioneer! We need more strong, happy, fun single women as examples to show others that they, too, can be happy! Don't feel guilty, don't feel shame, don't feel anything like that. Just say "I love and accept myself, and am a happy joyful loving single 40 year old woman"!!!