For our readers who are not aware, General Certificate of Secondary Education (GCSE) is an academic qualification awarded in a specified subject, generally taken in a number of subjects by students aged 14–16 in secondary education in England, Wales, and Northern Ireland.
There are many things that can cause moodiness, and stress is certainly one of them. You acknowledge that you are under stress from academic pressures and this can tax your coping skills to the point that you blow up or break down at the slightest incident. Mood swings can also have a biological component and the overt symptoms are representative of an underlying chemical imbalance associated with a mood disorder.
In either case a visit to a mental health professional would give you a much better idea of what is going on with you. If it is stress related the therapist can work with you on stress reduction skills or time management that will help make your life more manageable. If the therapist feels that a mood disorder is at the heart of your problem then he/she will most likely refer you to a psychiatrist for an evaluation and diagnosis. The psychiatrist may suggest a course of medication if your symptoms warrant it and mostly likely have you follow up with a therapist.
It has to be frustrating to feel like your life is on a roller coaster that you have no control over. Getting help is the first step in regaining control over your life and making you more at ease with everyday challenges.