“I can’t imagine life without orgasms, what can I do?”
Sudden inability to reach orgasm can be a warning sign of a major medical problem, such as heart disease. Nothing I say can substitute for a medical evaluation, which could be lifesaving.
That said, your emphasis on your weight leads me to wonder whether your feelings about yourself as undeserving of sexual pleasure might be affecting your sexual response. The brain is powerful, and if you condemn yourself for your weight gain, this might be dampening your ability to connect sexually with your own body. We can be desirable and sexually responsive whether slim or curvy—I hope you’ll work on accepting this. Eating healthy foods and staying physically active helps our sex lives because our bodies function better, but that’s independent of whether we’re at some “ideal” weight or not.
Note to your grown sons: Your mom is acting her age. We are sexual beings lifelong. Stop being embarrassed by her and support her.