Yes I have felt lonely. Started doing hospice for people with 6 months to live. My own problems shrank quite a bit during that, but I was more prone to depression.
I did make some friends that way but it was sad to see them die.
Do you ever read some of these studies? more people are spending more time online. For better or worse.
Do you like painting or crafts? Take a class. Whatever you do or experience there is probably a group for you. Online yoga at youtube is fun.
But the fact we are alone is hard to accept. But the other people feel that way too but their pain is not as close to the surface. The grass always appears greener in other's yards.