Empty-nest, menopause, stay at home and realizing I can never have the life I want

I quit an amazing career for a special needs son, and now 15 years later at the age of 51 am realizing I will never have the life I want. I have spent nearly 5 years looking for jobs without even one interview. I got an additional degree, tried to change careers, nothing works. I am surrounded my successful women living their best lives which only make me more painfully aware that I have nothing. Most of my friends (kid’s friends mom’s) have moved or are too busy with their careers. Volunteer work has proven to be superficial and doesn’t help connect me with people my age. I fell alone and empty and quite depressed. I have always been driven and an optimist but I have been beat down so much I don’t see light at the end of the tunnel. Any inspirational stories out there to prove me long? How do IO not sit alone in the house each day crying?