I have a bad temper, and I get irritated over small things. What is happening to me?

Hello doctor,

I am a 17-year-old girl, and lately, my mood is not good, and I think I need counseling for that. Since my temper is bad, I easily get irritated over small things like doing chores, since it is my vacation. My mood is always off, and I have a habit of thinking bad things at the back of my mind, and I realize that it is not a good thing. When I realize that I am doing that, I scold myself and get more irritated. I thought it was because of PMS, but now I think it is not. It scares me that I am already a bad girl and a bad daughter. It came to the point where I do not want to see or talk to my family at all. I got so irritated and used to get all upset, and then I would realize that I was a bad girl, then got more irritated then eventually would cry in the end. I tried calming myself by taking deep breaths, but it is not helping at all. Instead, I got more irritated. What is happening to me? I feel guilty about my actions, and I get angry at myself because of my actions. I cannot control my emotions anymore. I should fix myself before I start my classes, and I only have a month left. I cannot bear to see myself like this again, and I cannot do anything to fix myself. I really need help. I have a sister who is a psychology student, but I know she cannot help me. I hope you can help me. I really, absolutely, need help.