What should I do about these dreams?

I keep having these awful nightmares but last night I was sleeping on the couch and I had a dream that my friend was being taken by foster people so we held each other and cried, Her still in tears said she had to show me something, we walked in the bathroom so we would be alone, then she pulled out a note but then she dropped it and grabbed a hold of me going TSSSSSSSSSSSSSS, TSSSSSSSSSSS, For some reason I knew I was asleep on the couch because I could feel the leather under me but I was paralyzed and when I say I couldn't move I COULD NOT MOVE I tried to get up so I could go get my mom but I could not for the life of me move, So the image of my friend doing this to me STILL in my head I starting getting scared, I tried to scream hoping someone would come wake me up, but all I could get out was a heavy breathing noise but it was very faint, I know this went on about 20 minutes before My friend stabbed me and I finally woke up.. Is this normal? This has happened to me several times before and I hate it! Is it called anything? My aunt told me to go straight to the bathroom when I wake up from these dreams and pee and it won't happen again.. But I don't believe her... What should I do? I have also has several people in my family did this before..