@lina
Yes, what is how insane strangth does always work, except your brain is smart enough to learn from injuries and set a limit on your power.
What you said would happen only once, and most likely in a micro dose, while you are growing the power.
https://en.m.wikipedia.org/wiki/Hysterical_strength
Yes, you do already have the strength to cripple yourself. You just cannot willingly use it.