I'm shedding regrowth and have scalp discoloration. Possible AGA?

This needs an in-person evaluation. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

With this particular history it is really important to get a definitive diagnosis. This is best done with a skin biopsy. After diagnosis an appropriate treatment plan can be designed. 

This definitely requires a more in depth examination than can be done over the internet. For now wait on your biopsy results and your doctor's interpretation of them because without other information there's no way to give you any sort of diagnosis here. AGA seems very plausible here.