Sorry you are feeling a bit aimless, it's probably part weather/part illness. I think healthy people have a repertoire of things that we just can't do. They can go out for a mooch, paint a wall, bake a cake, whatever. They are available to socialise. I just said to DH "I wish we could go and do something nice", his response was "Sorry, you know you are supposed to be resting." That's it, really. I am trying to recharge my batteries but it's a damn slow business.
I am a great planner (although hampered by a shit memory!) so I make myself think about Christmas and birthdays far far in advance so it's all ready at the time. I do Christmas cards/presents in early November, and wrap a couple a day.
If I had any energy to spare I would do some batch baking to make life easier during the week, but if I were confined to the sofa I'd probably just make a plan for easy stuff to have in stock. Don't try and be virtuous and busy, your body is saying NO.
Is there anything you are interested in that could fill a few hours while you are physically resting? I get interested in all sorts of odd things which I research intensely so I look as if I'm resting on a sofa but actually I'm down a rabbit hole!
Hope you find something to cheer you up.