Hi James, welcome to PC!

Have you ever been treated for depression and/or anxiety? Just a few things jumped out at me like "...dread the moment when I'll be home again..." and "...distracted from the feeling however it's still there..." Among a few.

First a physical check up should be had then a mental check up.

I don't know, but it feels like depression the way you speak it. Depression doesn't have to be under the covers for days type, it can be an energyless state of drab existence.

I think you should at least get in and talk to someone. Good luck!