@evinann, GCA is nothing to mess around with. I would seek help from a rheumatologist as soon as possible, or teaching hospital or major health facility. Here's some information from Mayo Clinic:

"The best way to confirm a diagnosis of giant cell arteritis is by taking a small sample (biopsy) of the temporal artery. This artery is situated close to the skin just in front of your ears and continues up to your scalp. The procedure is performed on an outpatient basis using local anesthesia, usually with little discomfort or scarring. The sample is examined under a microscope in a laboratory."
--- https://www.mayoclinic.org/diseases-conditions/giant-cell-arteritis/diagnosis-treatment/drc-20372764