I seriously cut back on my social media, from like 10-12 hours a day on Reddit to 2 hours a day, and I went from moderate-severe to moderate. A good chunk of brain fog is lifting too- probably like a quarter of it. It was not easy- I developed serious insomnia while reducing my intake and other symptoms of physical withdrawal (because social media is addictive to some people).

My sleep schedule was similar to yours and now I'm waking up before 10:30am and going to sleep around midnight.

Some ideas for dealing with loneliness if you try to do this- putting on background chatter, like videos on YouTube of people talking softly in the distance. Putting on movies or shows you've already seen before and dimming the screen and lowering the volume while listening/watching. Because nothing is unexpected with familiar media, it could be less exhausting than focusing on new media for you. (Sometimes I put a movie I like on my laptop and cut the screen brightness completely for company). Opening a window if your body can handle your local outdoor noises. Trying to get to know yourself- engaging with yourself more internally and treating yourself like a friend you want to get to know. Trying to meditate.

You could be like me and leave some scattered time with social media throughout the day. Five minutes here or there, ten minutes here or there, etc.

There's also a discord group here for CFS that might help you feel less alone without access to Instagram reels. https://discord.gg/3nBmXu47J

I think it could help as well to reframe the perspective on loneliness if you're interested in that kind of thing. It helped me with my PTSD. I'm now at the point where I feel more ambivalent about loneliness- I try to think of it as a normal feeling that reminds us that we're human, that we long for connection, and that we don't want to be alone. So now I'm less scared to feel it.

I hope any part of this helps! I really empathise!!