I've been having mood swings, not sleeping well and sore breast.i went to see my gp and he did some blood tests and he told me that i am pre menopausal?

You mean perimenopau: Your age of 37 years is quite young for these symptoms to be due to hormonal changes that occur if one is getting close to menopause. You should go see a psychiatrist and seek medication for mood swings and poor sleep which apprear to me to be possibly symptoms of depression. A good antidepressant may be helpful to control your symptoms.