I'm really scared I may have a heart problem. Yesterday I felt terrible weakness in my legs, could barely stand without feeling like I'm gonna pass out. I also have muscle twitches in my chest and flutters, rapid heartbeat, loss of appetite, and shortness of breath. I know I tend to hyperventilate a lot so maybe that's why. I haven't even been to the doctor yet to see what's wrong. I go to the doctor in 2 more days everyone says it's just my anxiety. Also, does anyone else have an irregular heartbeat? I'm only 18 I hope it's nothing serious going on!