Im 14 and i have been very dizzy and forgetful?

its so weird im just so dizzy all of the time and some times ill have these out of body experiences where i get like tunnel vision and im not im my body anymore is what it feels like. also when i stand up from a sitting position sometimes i get tunnel vision and its like im exhausted and zoned out for a second. whats up with me. by the way im a guy if that matters at all.