Sometimes it is difficult to understand why are we thinking so much and why is it even happening to us. This is partially because of things bothering us at a subconscious or unconscious level. Consult a psychiatrist/psychotherapist who would help you understand what is bothering you and how to deal with it in a proper manner.
Also certain lifestyle modification changes might help you get back to your normal sleep routine.
Poor sleep can cause frustration and anger outbursts which can in turn disturb sleep and the vicious cycle continues.
Try yoga/meditation as well and if severe problems persist, consult psychiatrist for may be temporary prescription depending on your other symptoms as well.
Next Steps
Visit a psychiatrist/therapist
Health Tips
Try yoga/meditation/physical exercise