I understand you are anxious for an answer to your question, but just to clear a couple things up about this website.
We are all volunteers here. We "work" out of our homes or from work if we have a free minute............we are not sitting in some office collecting a paycheck. We make every attempt to respond to people as soon as we can, but sometimes it just takes awhile. Especially on holiday week-ends like this one. I have 25 people in my backyard and I just ran in to grab something and I saw your post. I'll happily take some time away from my family to respond because I understand your anxiety.
You have described some pretty classic symptoms of a panic attack. Have you been under a lot of stress lately or has something frightening/tragic happened in your life or to someone you love and care about?
One of the most scary aspects of panic attacks IS that they seem to come out of nowhere for no apparent reason. But there usually is if we give some thought to our lives over the past several months (even longer)
There are some medical conditions that can trigger/cause/mimic panic attacks which is why it's a good thing you're seeing your doctor for an evaluation soon.
Once they have ruled out a medical reason for these attacks, then they can deal with the only card left on the table which is anxiety.
I virtually NEVER tell anyone to Goggle anything, but if you go to the Mayo Clinic website, do some reading on anxiety/panic attack and their symptoms. I think that will ease your mind somewhat. Or spend some time reading posts on this forum and you'll soon see that your symptoms are very common.
IF and when you have another attack, put a cold towel on your head, lay down and concentrate on your breathing. Take long, slow deep breaths and exhale through your mouth. Try to relax all your muscles and while I know it's difficult, try NOT to focus on what you're heart is doing. The slow deep breaths should slow your heart rate fairly quickly. What causes most panic attacks is a sudden "dump" of adrenaline into our system. That is the "fight or flight" hormone that helps us when we face real danger. And that's why it's so scary when it happens when there IS no danger! When we relax and breath deeply and calmly, the adrenaline is absorbed and those frightening feelings will begin to abate. Another thing we do when we panic is called hyperventilating. We "over breath," and that throws the balance of oxygen and carbon dioxide way out of balance. It can cause a great many of the symptoms you've described and is one reason why learning to breath properly through a panic attack is so important.
I am NOT a doctor, but I've suffered panic disorder since I was 12 years old. I'm 64 now, so I'm pretty sure you've just had your first experience with panic.
I know it is a holiday week-end, but if your panic becomes unbearable to you, have someone drive you to a walk in clinic or an urgent care center. They can give you something to help until you see your doctor.
Just know that nobody had EVER died from a panic attack even though I know that's what it feels like is going to happen.
I hope this has helped a little and that you'll let us know what the doctor says.
I know this is also hard, but try really hard not to focus on all the weird little things your body is doing. Deep breaths! Anxiety is a powerful enemy.
I wish you the best. You're going to be OK