Lone atrial fibulation

Hi, im a 22 year old male with no medical history besides anxiety and benign pvcs labled by a few different doctors.I have no risk factors except for smoking for 2 years when I was 18.About 10 days ago I went into Afib, I convereted when I was off drugs.They did a echo chest xray and other things yet they could not find anything wrong with me or my heart and they could not figure out why I went into afib since everything had normal findings.They placed me on sotalol ( betapace) 40mg twice daily.Since this has happened it has really effected my anxiety issues and am now having anxiety attacks thinking another episode is going to happen and now im thinking about dropping out of school because of all that has happend and me not able to control all the anxiety that is going on in me.My question is, ive heard that people can actually die from sotalol, but at a dose of 40mg twice daily with a normal heart could that happen and is it even worth taking since I dont even know if these afib attacks could come back?Also with my afib im still very confused about it, since I got afib for no apparent reason is it possible I could drop dead from a heart attack or sumthing even though im pretty fit and have no defects or health issues?

[Encephalomalcia]

Here is a good website that I refer to often with our own family history of heart disease.  http://www.drugs.com/cdi/sotalol.html

Make sure to take your pulse during the day to make sure that the medication is not bringing down your heart rate too far.  Afib can happen and then not happen again for awhile or a person can live with Afib.  Once the heart reaches a beat of 200 per minutes it does not work well and shakes.  You should know if your heart is beating too fast as it is hard to breath once is reaches about 140 to 160 beat per minute depending on the person.  Young people sometimes have afib problems in their teenage and yearly twenties so this may be something that you will not have for the rest of your life.  If you are worried about a heart attack, you can take a 81mg aspirin per day coated is best so that it does not upset your stomach.