Panic Disorder

For the past 3 days, I have been having panic attacks nonstop. If I stand up, I immediately have one. I don’t know what it is… I wake up sweating, heart rate at 144, running off of adrenaline, like I just don’t know how to get them to stop. I finally feel okay, and then I start thinking about it, and it causes it to happen again. Never in my life has this happened to me before. It wouldn’t worry me if my heart wasn’t pounding out of my chest 24/7. Please help. I can’t live like this.