Hello there we understand your feelings your condition. But then we.would like to say that there are while a lot of reasons for this but yours seems to be of taking too much of pressure. That bursting of feelings is because of gush of frustration to show. To come out of this you need a break and you will have to share your feelings with some whom you're close with. This will help you to improve.
Hello dear, at the young age of 15 years, its very difficult for me to understand your reasons for aggression... You have not provided some very important details like any ongoing stressors, duration of your irritability, if that is a change or is that how you have always felt, any other physical or mental symptoms like wt changes, ongoing medication, accompanying drug use, crying spells, self harm or suicidal thoughts...amongst many others. To really improve the difficulties , it will be best to consult a psychologist or psychiatrist to understand why this is happening, to learn anger management skills and adaptive coping for any ongoing stress. Kindly do that at the earliest.
Meanwhile, try to engage in a healthy lifestyle which includes daily walk(shall help control your aggression), meditation(to lower your basal level of arousal), spending time in persuing your hobbies, meeting friends and other recreational activities. Avoiding situations where you feel irritated, taking a break in such situations rather than immediate response, shall help in regulating anger too...but details can be learnt in person from a psychiatrist. Don't hesitate to consult one, good luck!