Headeach and sadness. And suggest me!

Mam I am facing very huge prob. I feel sadness and some pain in my left side of my head . I want to stand on my feet to make my carrier to live a happy life but due to this problem I can't do anything . Symptoms are like this I want to smile but i can't I want to talk people and make them happy but i can't .. Two days in a week I live happy and other time I live sad and painful life. Sometimes I feel gud after I fell sad after I feel gud after I feel sad and it is continuously with me . This problem started 2 years before. Before that I was fit .my body is gud, sleep is well but not timely. Confidence is very low ... I'm taking medicines regularly but it do not work enough. Pls tell what is my problem and suggest me