You mentioned that you are light sensitive, Irlen Lenses really help with this problem. I have also found that for me personally, that when dealing with my light sensitivity, my other sensory problems are less problematic.

http://irlen.com/index.php

Although Irlen Lenses are expensive they are worth the cost.

For when you aren't at work, but you want to concentrate on something, do you have comfortable headphones? For me they don't even need to be connected to anything to help, but listening to Heavy Metal Music or Opera helps me just by itself.

I have a Therapy ball. I like to bounce on it. Sometimes I sit on it with the laptop on my lap. Probably not the best thing to do, but it lets me pretend that I am getting some exercise while I am sitting on my lazy butt.