Strong emotions, mental instabilities, surprises, etc… create a negative impact towards our ability to ration, yes.
Does that impede our will? Sure. I will that I never sin again, nor want to. But because I am disordered, that’s probably not going to happen. The problem is original sin, and that has nothing to do with God. Without original sin and our disordered state, strong emotions wouldn’t blind us from executing our right and proper will. Or, if we are “spooked” in Heaven after we are made perfect, will we suddenly commit a sin and fall? Of course not. Therefore it is a reflection of our disordered state.
This has nothing to do with God, unless you’ll go on to make the further claim that it’s God’s fault we have original sin, etc…