No worries @GhostGirl123, you definitely deserve to know you're not alone in this struggle. When it comes to filling the time... for me, it depends on what I'm capable of. I used to enjoy hard exercise on the weekends, especially cycling, but that's really harmful for me now, due to my chronic pain condition. I also used to take long walks and photograph things, which would take up a surprising amount of time if I listened to music and wandered very far. I also used to make art and do a lot of writing, but I no longer feel any inspiration or enjoyment with those things, which has been pretty scary.
Nowadays... Reading books, marathoning TV shows, and watching movies is more accessible for me. I don't have to aim for an outcome or achieve anything. Since I have zero energy most of the time, activities focussed on consuming rather than creating are better. I would prefer to see my friends, but they aren't really around, and I'm very afraid of making new connections after experiencing harassment. So I've had to figure out what's possible while I'm isolated and unwell.
So, all that said... our situations might be completely different, but if I had to give any advice, it'd probably be to experiment and try new things. Don't try to force things to happen. I've never been more miserable than when I'm forcing myself to create art yet not enjoying it 😅 If you feel discontent, frustrated, or frightened when you're alone, it's good to try and figure out why that is. Filling the time with activities is only half the story, if that makes sense.
And hey, if you're not like me, you might enjoy seeking out the company of other people. Depending on your area, there could be lots of public and free socialising events that you could attend. Maybe volunteering would be a good idea, at an op shop for example?