About 36 hours after my dose, or the 2nd night, I woke up at 6am with a racing heartbeat of 90-100 beats per minute.  My normal sleeping heart rate is in the mid to high 40's, or low 50's. I had no idea why my heart was racing at 90-100 beats per minute but I quickly realized there was something wrong.   Waiting at the hospital waiting room it was consistenly around 83 bpm, very high from my normal resting heart rate of 53.   I also had some vague chest tightness but only for a few moments, and a vague pain, again, only for a few moments.  Mostly very rapid heart rate that lasted for HOURS.  and a lot of shortness of breath.  They did tests for some hours and could not find anything officially heart-wise and as I was laying there trying to relax my heart rate came down slightly, into the 70's and touching 69 I was lay still and as relaxed as I could, so they discharged me.  Back in the car my bpm was back in the 80's as I was no longer laying down and while driving home back to 100ish, but I felt a bit better knowing I wasn't having a life threatening issue in the moment.   I was fortunately able to sleep, making sure to keep my arm at my side in bed and not putting even 1 bit of pressure on my chest, and not sleeping on my side or my chest, as I slept on my side that night of the problem and that is when my heart started fluttering I believe.   So if I lay in bed on my back and lay completley still, I have been able to sleep and not feel wierd chest feelings as I normally might.  But the scariest part now is the extreme shortness of breath.  The first day after (day 3 from shot - Thursday, shot was Monday at 4:30pm) I could barely go 5 steps without being completely winded.  I could barely go up or down stairs, or do much of anything.  Each day I get just slightly..better...as now on day 5 I can go up the stairs in only 1 minute...instead of 2.  I still have to go step by step and it feels like I am climbing a mountain and then am very tired and must rest.  I am hoping I continue to get better but I am very concerned if this will have any long term health effects for me, as that is the entire reason why I avoided covid to such a great degree, as I knew I had some kind of allergic asthmya like condition perhaps, but not officially asthyma (that I know of.)    Presently now Sunday night day 6, my heart rate is often in the 70's although when sleeping and resting it does go down to mid 40's during sleep and 50s sometimes when still.  but other times sitting still it can be 70's or 80's which is abnormal and my ox level often goes to down to 93, while I am sitting and doing no movement.  It also often says 96 or 97, again while doing...nothing. and being still.   While walking just a few steps it went down to 89 on the first or 2nd day.  I have not exerted myself much as I cannot much, and out of fear of creating another problem, or something worse.       I was givin no treatment and they told me I had "stress", which clearly I do not, I was as relaxed as possible which thankfully brought the bpm down to 69/70's range, but for me that is still much elevated and I knew something was not right, but I understood that they likely could not find anything and it was getting busier and they likely had to fill the beds with others.    I am on day 6 and this feels like it could last likely weeks, or months, again, I have been given no medication and have no diagnosis and medical professionals and been of very little help, besides doing some tests and watching me during the intial heart rate issue.   This issue must be studied much more to understand what is happening and it is unnaceptable that not enough people know these risks.