I work from home (part-time). I have an upholstered chair whose back is just the right height for me to rest my head on if I slump back and put my feet on a step-stool. Sounds bad, but it makes all the difference. I encourage you to get a chair that allows you to rest your neck.

I also have a little table that's the height of my elbows when I'm sitting down. I put my mouse on it and keep it right next to my chair. That means I don't have to extend my right arm and hold it up while I'm using the mouse. And I have a wrist pad for my keyboard so I don't have to hold up my arms while I'm typing.

Abby