I understand your situation. Most of us get irritated and angry at times, and regret later on. This is not a comfortable situation because you do not want to hurt people you love and care about, but at present the situation seems out of control.
Do not worry, you can overcome it. You just need to sit with yourself and find out what is making you unhappy. When we are not happy with ourselves, satisfied with our work or activities or frustrated with anything than we get irritated. Sometimes the cause gets buried in the subconscious mind and we forget why we are getting disturbed.
You can also write down each activity and think if something is bothering you, especially in your case your college routine or studies. You can also ponder over your relationship with your family members, friends or classmates who may have said or done anything that made you angry.
Once you find out the reason, it will become easy for you to practice affirmations, such as I FORGIVE EVERYONE, I FORGIVE MYSELF, I AM RELAXED.
Remember, do not feel guilty. We are not perfect. You have become aware of your present situation, but this is temporary. Just practice affirmations.
My best wishes in your journey. keep in touch.