I've always had a fast heartbeat, I think. But now I've been noticing that I do have a fast heartbeat. And everytime I check my hearbeat I m usually nervous or something and it s above 120. Also I can t really breathe properly, and that mucus was dripping down into my throat. Doctor said I might have a sinus infection but just gave me anti-biotics. I also have mono so I m just really tired. And I don t really have chest pains, I m just sore around that area since I just benched for the first time. I really have mono, because they took a blood test, but every time I try to relax it doesn t work. Well my nose was congested 4 weeks ago, and it still is so that s why I said what I said. Well I m only 15. But the fact that my dad has high blood pressure, and has a constantly stuffed nose kinda freaks me out.