Well there are a couple of possibilities. The first, one can translate it just as you asked: fortitudo e dolore venit "strength comes from/out of pain" But if you want to simplify it, one can just use: fortitudo per dolorem "Strength through pain"
you just do it. you force yourself to get up. you force yourself to put on foot in front of the other, and god damn it, you refuse to let it get to you. you curse. then you go about the business of living that how I've done it