There are still many things left to do alone, I am a loner and I see beautiful things just in nature, alone too.
My family isn't into that stuff so I do it alone, and I enjoy the peace. And if I were to be single again, I'd love it, with age I have grown to appreciate time, simple pleasures. By when I said single I didn't mean widowed so I do not want anyone to think I meant that.
You can enjoy sunsets and sunrises, rides around places, museums, smelling flowers at a plant nursery or public gardens, though because you feel down right now, there are things that a person alone still can enjoy, so do not lose faith, give it a try, maybe even start with a walk in the park, or along the shore if you happen to live near one of the coasts.
Give it a try

((((((((((((( lost_lonely)))))))))))))))))

In giving advice seek to help, not please your friend
SOLON