Hello and welcome to HCM
You seem to have developed an allergy after weeding the yard, to some plant/insect etc. Due to which you developed a rash. Mild swelling in the area may have caused difficulty in bending and other symptoms.
Also contact rashes may spread from area to area, along with symptoms such as swelling, pain,fever and sometimes severe reactions like breathlesness and
fainting, which you did not have.
I would advise you to start on antihistamines such as
fexofenadine or levocet twice daily for 3 days and then continue every night for 5 days. Apply a soothing
calamine lotion over the rashes 2-3 times a day. If you are still developing rashes apply a
mometasone cream twice daily for a week.
If your symptoms are severe do visit the ER and get a
cortisone and antihistamine shot.
Avoid pain killers and any other substances that you are generally allergic to. This should subside your symptoms.
If you are still feeling no relief in 2-3 days, consult a doctor who may suggest a few blood tests and rule out other causes of your rash and swelling.
Hope this helps.