Got a fever for 6 days, dry cough and cold....cont..?

and my throat became painful and itchy. i started gurgling warm water with salt. My aunt told me that it might be strep throat and if not treated could lead to heart failure. I didn't take any antibiotics at all and never went to the doctor. now, when i cough my chest hurts..i'm afraid that i might have heart damage due to strep because i didn't take any antibiotics at all. my auntie is just making me afraid that it's strep..is she telling it right? I haven't went to the doctor yet..i think she has a fraud diagnosis.