No; sitting in bed,not using your muscles will cause more problems and not just with your penis. Gravity is affecting your dick whether you are standing up or laying down or standing on your head. You body is designed for that. Laying in bed is great for forming deep vein blood clots, pulmonary edema and a whole host of other medical issues. That how old people die. Is that what you want? Not me I’m going out on my feet!