What doesn't kill you only makes you stronger.
Ask a Vet with an amputated limb if they feel stronger now or before the limb was taken... I'd bet before. Injury, all injury, is by definition a lack of perfection.
What doesn't kill you, more often than not, makes you weaker, more timid, more cautious, slower... Not stronger.
Sure, we can learn from the past, become more resilient. We can use pressure, under certain circumstances, to build resistance based strengths, like a body builder pushing back on the resistance of the weights...
But by no means is the saying: "What doesn't kill you only makes you stronger" an accurate portrayal of Truth, nor should it EVER be spoken to someone in pain.
The enemy comes ONLY to steal, kill, and destroy, that's why the pain/attack came, not to make you stronger but to kill you.
God's Grace brought you through but He didn't bring you to...
God's Grace can heal you too.