Here's a list of fun things that require little physical work.
1. Scan in a 5 pound note, print it off and cut it out. On the other side write something like "I'm watching you". Then crumple it up a little and lightly glue it to a pavement or similar that you can view from your window or a hidden place. Then wait for someone to go by and get excited when seeing it from a distance, they'll pick it up and read the writing on the other side. They'll look around in a panic. I love it.
2. Go around the streets at about 3-4am painting people's cats. Or if you're unable to get around just lure them to you with treats, paint them and send them on their way.
3. Write a sitcom about 3 Gay Guys that go on a road trip where 2 of them die. (I'll bet you've never even thought of doing this before).
4. Try and get some medicinal cannabis. You've really got to milk your situation for all it's worth.