Bmosbacker posted an interesting YouTube video a while back, arguing that you should probably not use a task-manager like Things to manage projects. Of course, you can have tasks like « work on this project », maybe with a couple of GTD next actions to move things along, but you should probably manage your projects elsewhere: Obsidian, for example.
That said, I think I understand where you’re coming from. If I can’t have an overview of all my projects, I get anxious. And when I can see them all, I get overwhelmed.