I Have Started Having Insomnia After Shifting From 1st Shift

I have started having insomnia after shifting from 1st shift to 2nd. I started only sleeping 4 hours a night. After about a week I developed severe depression. It's been almost a month and now I can't fall asleep at all anymore. My body feels exhausted yet I feel wide awake. I also seldom ever yawn anymore. I was prescribed trazodone for sleep. With 50 mg, I sleep 2 hrs, then wake up with terrible anxiety. Do I have fatal insomnia? What should I do about it? I can't concentrate at all anymore at work and I'm scared of losing my job, please help. I've been averaging less than 2 hours of sleep for almost a month but most nights, I don't sleep at all.