How could a adhd/autistic [aspergers] adult, like myself, calm down when angry?

A therapist can help: You recognize your " rumbling stage" ; teach you self-calming techniques. Your insight ; motivation are impressive! effective therapies for people with asd's need to be intensive ; repetitive. Even as an adult, you'll benefit from knowing what events trigger your emotional over-reactions. Medications are part of treatment of adult adhd ; of irritability in asd. See http://www.Autismspeaks.Org.

CBT: Cognitive Behavioral Therapy is a technique for dealing with stress and anxiety. Other stress reducing techniques include meditation, yoga, and healthy amount of exercise can be helpful.