Nightmares.

I keep having nightmares about things that happened to me a while ago when I was a little kid. I was around one of my mom's ex's and  he abused me physically, mentally, emotionally, and sexually from when I was 4 until I was 8. I feel fine most days and am trying to learn to live with that being a part of my past. But, sometimes I have nightmares about the things that happened to me. Like I'm re-living my memories and those specific events. It seems so real. It's been happening more and more for some reason. I wake up with my heart racing and sweat all over my body. I can't really do anything about it. I've tried relaxing before I sleep and tried thinking of something nice before I sleep. I've slept in the cold and slept in the heat. Nothing changes it. I've tried eating different  less sugary foods. Nothing really works and these nightmares are getting longer and worse.