Curious About Stiff Neck and Heavy Arms and Achy

I have been avoid most strenuous activity for months,hoping to ward of high pulse rate and trying to work in a little activity everyday.Yesterday I decided to go outside and shovel a little snow and picked up a few heavy things.I came in trembling all over but got over it.I rested and last night I was propping up while using the computer and noticed it was hard to swallow a couple of times.i didn't really think much about this,it has happened several times in my life but today I got up and got busy and was putting the garbage out with the cold air coming in.My arms immediately starting feeling heavy and legs aching and my neck completely around it felt tight and tense all the way down my muscles over my shoulders.I started laying down and relaxed and it seem to subside.I got up this even and took a shower and still noticed my neck and shoulders and arms feeling very weird and legs aching too..Could this be having tension and anxiety while doing physical activity and me not notice it till today ?Or is there a possibility that the heart is involved..Everything seems ok but the total stiff neck thing and heavy arms has me concerned.Anyone else ever felt like this after getting back to activity and is it normal for anxiety to cause tension and make you feel this way?Anything you can tell me would be greatly appreciated

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May all beings everywhere plagued
with sufferings of body and mind
quickly be freed from their illnesses.
May those frightened cease to be afraid,
and may those bound be free.
May the powerless find power,
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the children, the aged, the unprotected--
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