Aaaagh!! Rapid Cycling

The last few days I've been waking up feeling relatively normal.  As the day progresses my mood shifts into self pity, loneliness, and depression.  And by the time I'm ready to go to bed I am so depressed I start crying and having thoughts that this life is not worth living.  I go to sleep to wake feeling normal again and again by bed time I am in the same depressed state... how I hate not having control over my moods.  What I would give to have relief.  Such is the bipolar life.....