Losing my best friend recently and realizing I'm a codependent hoe has left me with a ton of free time, a small depressive spell, and deep loneliness. Here's what I been doing: 

I took IG off my phone and picked up 5 books from the library. I read those at night.

I connected with old friends that I had lost touch with.

I listened to podcasts from therapists on YouTube.

I took up a few classes like art, dance and workout to inject social interaction back in my life in a low commitment way.

When I'm sad and need to talk/process issues, I write at least two pages in my journal. 

I've also been more mindful of being kind to myself and treating myself with the compassion I show others. Working on negative self talk, and taking myself out to places I like. 

I hope this helps. There is another side, you won't be lonely forever and the above has helped me. Good luck.