While driving, you can do isometric exercises, contracting & releasing muscles from your toes to your shoulders, which can kill a lot of time, and on your bed, you can use a bungee cord as a resistance band: hook one end to something stationary, & pull against it, slowly. To use it for leg exercises, wrap your end around an ankle. anything that weighs a couple pounds, like a heavy can, or flashlight, can work for weight lifting for your arms, though you'd probably want a weight band for your ankles, lol.
I have frequent pain in the trapezius muscle, running from hairline at the nape of my neck, all the way down to my lower back, and a great way to relieve that is to lie on your back, with a tennis ball placed under the muscle, then you move slowly, in small increments. the pressure really helps!