My mood swings? why does this happen?

You have a manic depressive or anxiety disorder,all to common now days,often caused by stress,personal tragedy,and sometimes from birth ociated with a chemical imbalance in the brain.Often these disorders are of short duration and it is only a few who will be affected permanently.Consult your G.P. who will ess you prescribe some suitable medication to alleviate the symptoms,and he may,or may not refer you to further mental health professionals.Please see your G.P. to at least begin treatment quickly.