Sorry to hear about your medical issues. Say, here's a thought: You're a freelance guy with a home office. I'm a freelance guy with a home office. We sit a lot during the day, then sit a lot on our bikes.
Are we sitting too much? What if the 8-10 hours (or more) you sit at a desk could be replaced with not sitting?
I'm seriously considering some sort of treadmill desk, because my backside gets sore all the time, and biking doesn't help.
Shrug.