I'm A 15 Yo Girl. Recently I've Been Really Clumsy

I'm a 15 yo girl. Recently I've been really clumsy and forgetful. I will walk into a room and promptly forget what I'm doing. I also forget names and numbers. I switch around words when I'm talking and sometimes stutter, I walk into walls sometimes. I have trouble concentrating even when I have the energy to do whatever it is I'm supposed to be doing. I constantly have really mild headaches. What is wrong with me?