Beth, I go through periods where I can't sit around the computer at all either. I did find online one day a place that sells computer and monitors as well as keyboards for people like us. They use Ozone or something like that and some how it takes all of the icky's out and makes you able to be around the computer.
I can't remember the site but I'll try to find it for you in the next week.
If you want you can buy a cloth, it's a made from carbon. You wrap it around your nose and mouth while on the computer and it helps you be on a little longer than normal. Also, I think putting bowls of zeolite under and around your computer helps. Or you can just buy the masks for those with MCS and it's lined with the carbon.