I think you may have an anger problem. It does not necessarily seem related to PMS but you might find that your emotions are especially unpredictable right before menstruation.
There are multiple ways to address this problem. One way is therapy. A therapist can help you to explore alternative outlets for expressing your strong feelings. A therapist can also assist you in understanding what is at the root of your anger.
You also might want to consider enrolling in anger management classes. Check with local mental health agencies to inquire about what services are available to you. Many anger management classes and programs are quite sophisticated and effective.
You could also read about self-help anger management techniques. Check Amazon, Barnes & Noble or your local library for books.
When your anger becomes overwhelming you react with physical aggression. This happens in the form of breaking pencils. Physically releasing your strong emotions can be very helpful. A better alternative is exercise. It is a great physical outlet. Through exercise you could release much of your pent-up anger and frustration. Studies show that people who exercise have a greater capacity to control and manage their emotions than people who do not exercise.
In addition to anger reduction and mood stability, exercise has other positive benefits such as weight control, increased energy and self-esteem. I am not suggesting that exercise is a “cure” for anger but it has the potential to neutralize or decrease the intensity of your anger.
It is important that you make a concentrated effort to address this problem. You have come very close to physically injuring someone. Take it as a warning sign that you are on the verge of out-of-control behavior. If you had not restrained yourself, you could have been arrested and might be facing jail time.
You have the choice and the power to positively affect this problem. Make the responsible choice and get help now before you do something that you may later regret. I wish you the best. Please take care.