"Surviving" is really good motivation. Whatever motivation is present right now isn't nearly as strong, but he's going to stick with it while it lasts. (And maybe this will become a matter of survival. Knowing how to fight without the force could be necessary if none the grimmer futures he has been contemplating pan out.)

Maybe he needs to approach this differently. When he's at his most effective with the force, he rarely puts too much thought into what he's doing. His mind and all of the chaos that goes on inside of it tend to hinder more than help. He can turn it down.

This time, he lets go of all of the advice and overthinking and just shoots. It's a clean hit.