Changing regions

I recently travelled to the US, and my app store worked perfectly fine. When I got home, i tried to download an app and it asked me if I wanted to switch to the US store in order to download the app, so I did. I expected that I would just be able to swap back, but now I can’t. I currently have a balance on my account of which it says I have to spend before changing my region. But when I try and spend the credit, it does not allow me to and says that it is not available in my region. How do I fix this as I feel like i am going in circles?