left forearm was sore?
are you a lefty ? is that your drawing arm?
a +20 yr old bow, hard to say whether its the bow, or you.
by you i just mean you didnt learn the bow in the 5 days,
first what poundage is the jennings bow?
did you just pull the bow out the closet and shoot?
or have a shop set you up?
matching the arrows to the bow is important, if you just went and picked up some arrows, may not be the corrrect arrows for the bow.
i wouldnt give up on the jennings bow just yet, unless i was sure it was off and too costly to adjust.