Struggling with Insomnia and Heartbeat in Head for 2 Years

Hello, I've been struggling for 2 years of my health. I've had dizziness, arrithmia, pulse in head, and insomnia. My main symptoms now are insomnia and the pulse in my head. Feels like if I had my heart in my head. I've tried all kinds of presciption drugs for sleeping but nothing works, even strong ones like Xanax do nothing for me. It's like my brain doesn't shut off, and I spend days without sleeping. I've been to doctors and several specialists and no one has been able to identify my horrible condition. I'm hoping someone on here might know something that may help, please if anyone can help me.