Your bones are directly responsible to your immune system. Your Bone Marrow releases Stem Cells, they are responsible for producing new cells in place of damaged ones. Thus they maintain your immune system.

Stem Cells are mainly released when you sleep, do meditation by putting your body into a straight posture & also Stretching helps a lot in mass production of the Cells.

Starting a task, failing, winning, losing again, reaching to a Rock Bottom position is a common phenomena. People don't need to get depressed, after reaching such a kind of dungeon, RELAX it happens with everybody.

It Is biologically necessary, as it cleares out the emotional toxins, whereas for doing that only laughing isn't enough. But crying for past events and meaningful reason is said to be good, but not for stupid-baby reasons.