Yes, anxiety cause this symptoms. The best way to deal with this is just ignoring it. Try to keep yourself busy, spend more time with family and friends.
Exercise and meditation can help you feel better and reduce anxiety symptoms.
Yes, Alvarez, those are among the many symptoms of anxiety. If you are worried about your heart, consider that it's been three days and you're still here. That probably wouldn't be the case if you were having a cardiac event. Only advice I can give you is not to hyper focus on your symptoms. Get your mind occupied on other things. Start a hobby, begin a home improvement project, detail your car, anything but sitting and focusing on your symptoms and sensations. Do that and they should diminish. Best wishes!
Yes anxiety causes those feelings.
Vitamin and mineral deficiencies also cause those symptoms.
You can get a blood test for Vitamin D, Vitamin B12, iron/ferritin