I agree with Nanners that you are most likely having some chest wall pain from 250 bales of hay. Try doing some deep breathing exercises. Also lay down and rest for a bit.
Do you have any med for your anxiety if the deep breathing does not work? If you do, I would not hesitate to take it as some of the benzos are muscle relaxants also and it may help with the pain.
If you continue to feel fearful and concerned, call your clinic and talk with the triage nurse who will advise you.
Gentle Hugs to you.