I have a gastric ulser, how can i get rid of it?

from the moment i wake up to about 1 in the afternoon, my body rejects food completely so i cant eat but i get so hungry that i get nauseous and the hunger pains are really severe. i get really dizzy and lightheaded and im pretty sure its due to my ulser. what are some ways to stop the hunger pain, nausea and dizzness and how can i make the ulser go away. by the way my doctor gave me zantoc? zantox? i have no clue what its called but i have no more. should iget more? i didnt feel that much better when i used it. he said my ulser is due to acid reflux and its also stress related. i need to make my ulser go away because last year i got the ulser in the winter and i stayed out of school for two months because i didnt know if it was a stomach flu or a stomach virus so i stayed home and when i finally went to school i didnt feel good at all and i got really nervous and scared so i didnt go in school until like fifth period every single day for like two months. i dont want the same thing to happen this year since seventh grade is the most important year for middle school- please please help....thanks =]