sensation of fluid running down my head

Hey. I'm new to this and i really need an answer! i'm a 14 year old girl. Lately I've experienced the sensation of water running down my head and also numbness in my hands and legs. I've also been getting terrible headaches and my vision sometimes becomes a little blur. I also feel disorientated and drowsy. Other than that, I've experienced a staggering loss of balance. I feel like falling down most of the time when i'm standing in one place for more than about 2 to 3 minutes. I can also notice a change in my personality. I've been keeping to myself and not really talking to my close friends and family anymore. I'm a top student in school but lately I've watched my ranking drop and i feel a lack of the memory power and concentration i used to have. I google-ed these symptoms and the most common result was brain tumor. I'm really worried!! Could someone please help me out here?