Violent in my sleep, help?

I've been sleeping in the same single bad with my boyfriend for almost a year now and I keep 'attacking' him in my sleep with no memory of what I've done; apparently i've been getting worse in the past month because i've scratched his face and chest quiet badly and bruised his arm. Can someone please help me with any advice on how I can stop hurting him, I love him and it's really upsetting me that I'm hurting him, although he says it's okay cause I don't know what I'm doing when it happens, but that's not the point, I don't want to hurt him and it's pushing us apart. Can anyone help?