Sometimes when I'm alone (rarely), I start to freak out a little bit and feel like I need the social contact. I know this isn't good if I can't be by myself. What I tell myself is that sometimes, I need to be alone to not be affected by anyone else. I need to step away to be able to see things more objectively.

There are some things that are better done on your own, like reading, stitching, making models, meditating. Find things that help develop you and that you enjoy those things.

Like lots of others said, working on yourself, but enjoying doing it and not caring what others think. You can go for a walk to the shops and back and buy nothing, and who would know that was your purpose - just to walk and listen to a podcast? Little things improve your life, even if it's 0.01%. They all, add up and one day, you can look back and admire how far you've come.