any because they are both the same
Sarah and I
Myself could be ich selbe, mich selbe, mir selbe, mich, or mir, dpendening on the context.e.g. I will do it myself = Ich werde es selbst tun.
It means she wants some space from you and your relationship. For what reasons, only she knows.
Sarah is a Hebrew name and therefore this is the way it is in Hebrew as well. In Hebrew it is pronounced Sa - rah It is spelled Shin, Resh, Hey (שרה)