Ok I need some help here and im going to be dead honest with this and it is quite serious for me. I think I have 3 personalitys each with its own name.
Now the two im worried about are 'The Grudge' and 'Sarah' while the third is just myself.

Now im 20 going 21 in a week or 2 and during my past ive had some difficultys to go through. I used to cut myself to deal with these problems but was forced to stop and in the end I think my mind just split.
Now im living with 2 extra personalitys. I class myself as number 3 as im usually just the host while things are normal and im willing to speak like now so this is me.

- The Grudge is pure evil absolute hate, anger, pain and disgust. He hates everything and everyone and doesnt need a reason to dislike you.
Now read this sentance in your head "i am me and only me and just myself". Now imagine saying that again but having a really horrible person just talking right over you and you can hear it as clear as day just like they were standing right next to you. I can be doing anything by myself and he'll just talk right over me saying stuff like "i dont like her, shes fat look at her shes a fat pig just cant stop stuffing her big fat face" @_@ now that shocks me!!! Im a lovely person and very quiet so never do i have thoughts like that but its him!! he just speaks right over me in my head and i cant shut him up.

- Sarah. Shes beautiful, stunning, wonderful, sexy, and happy. shes the best part of me and its strange to feel its a woman inside me but shes lovely. sometimes she will just completely take over me for days at a time. the effects are being totally femenine, generally happy and sometimes like to take control. i play lots of online games and i play my main accounts and characters but usually end up finding a female character on there under her name and a whole buddy list, emails and various other things.

Now what the hell is that @_@ do i have a problem? have i somehow managed to split myself in half with the 1 side being hate and anger and the other side being love and happyness with me in the middle acting as a host being neutral?
please help