give up?

What do you do when you don't know what to do? 
I had been diagnosed with Hyperthyroidism for a few years now. But I just went back to my doctor and he said my levels were normal. This can't be...
Why can I not control myself then? I'll be happy one minute and  he next I want to rage! Over the dumbest stuff too! And the crying, God the crying... idk what to do. It's hurting me, my relationships, my work. I just don't know.