In similar but slightly different light to this question: If one is mentally drained, should a person still daven? Even if that person cannot concentrate?
What is the halacha for one who is very angry, or very upset, or very emotionally shaken? Should they daven? There are sources that state otherwise, but I have heard in the past that they may not apply now, due to our lowly generation who doesn't guarantee concentration in any circumstances anyway.
Should one learn? Perhaps the study will help calm him down?
To avoid simple answers like "stop being angry", lets say that it's a situation where the distress is beyond a person's current "level" of self control, and they can't quickly calm down at the moment. They can try harder in future to improve their self control, but now is not the time for that.