Harming myself in my sleep.

So I'm a bit frustrated and freaked out because I keep harming myself in my sleep. It has gotten worse the past few months and I honestly don't even know what to do about it. I have horrible nightmares about a very abusive marriage I was in 6 years ago. The harming is always worse when my nightmares are really bad. Last night I managed to cut myself with my nails pretty bad. I peeled a layer of my skin off and didn't even wake up until after I had done it. I would think that digging my nails into my skin this hard would wake me up immediately, but I guess not. I have done this to myself several times. Do any of you have any experience with this?