Why do i have so many problems (sick wise)

i've been sick like all summer, near the end of the school year i started to stop getting hungry but i could still eat like a whole meal, but now i can barley eat half a cheese burger before getting full, and anytime i eat ANYTHING it doesn't matter how big or small i get really nauseas and im tired of it, i HATE doctors tho so i refuse to go to one so now im relying on u guys to tell me lol