Iv been felling like im going to throw up && p out all day im on my period, but im never like this.?

ok today is the second day of my period. and iv been outside taning in my back yard since about 12:30. i have eaten today but since about 1 o'clock iv been feeling like im going to throw up and everytime i stand i get dizzy. like i came in to use the bathroom about 30 min. ago and i was bent over the trash can about to throw up and its like i just cant. maybe its the sun plus being on my period but idk any other time im on my period and in the sun im fine. i also came in about 2:00 and ate a sandwhich and tea...but idk i cant stand feeling like this.