What happens if i d0nt drink water..s00n?

Umm i haven't drinkin anything in like three days Reson being because i'm nt hungry... If im nt hungry i w0nt eat and if i d0nt eat i dnt drink anyting.. 4 the last three days it feels like everyting is tighten up in my c0re and everything hurts in that area can s0me1 tell me whats happening and i need 2 d0 2 make it stp?