Wow, you've done just about all of the things I would have suggested! You've been so creative about trying to keep yourself occupied, and I'm sorry it hasn't been enough.
Have you considered trying a
self-paced online course? You can now attend Harvard from bed!
One thing I've enjoyed doing is transcribing historical documents--you can do this through the
National Archives, the
Smithsonian, and I'm sure many many other places as well.
There are also some fun websites where you can easily help scientists with their research (
this one is my favorite).
Also, if you have the mental energy maybe you could try a
very part-time job that you could do from bed? Jobs like transcription, taking surveys, testing websites, and many more abound. At least that way, even if you're still bored, at least you're making some money. That might make boredom a little easier to bear, and more fulfilling.
Please let us know what you end up trying! Many of us also struggle to cope with boredom, and would welcome your suggestions!