Hello! I Am 21 Years Old, Exercise Regularly( Training For

Hello! I am 21 years old, exercise regularly( training for a marathon) so my resting HR is normally 61. Yesterday I got a sore throat, awful headache, and could not get warm. I took some advil and that actually helped a lot. Well anyways my sore throat feels better today but my stool has blood in it and I got a horrible headache again, could not get warm, felt achy all over my body and my resting HR is 96. I do know its normal for your HR to increase due to infection. I do not want to see a physician yet because I just want to watch and see if my body takes care of these issues naturally. I know my body knows what to do when it gets an infection but just want to know if I possibly have the flu?