Anger outburst/aggression could a symptom to various psychiatric illness, psychological issue or even secondary to hormonal abnormalities.
Irritability with reduced sleep could be associated with mania, personality traits, hyperactivity etc.
Thus a detailed history evaluation of symptoms and behaviour is required to understand symptomatology and diagnosis.
Next Steps
Consult a psychiatrist.
Health Tips
If aggression increases and secondary to any active psychiatric illness there could be loss of judgment and harm to self or others, thus consider taking an opinion for the symptoms.