I was diagnosed w/ scabies. Did the permethrin cream 2x w/ the 1st apply 3 weeks ago and I am still itching like crazy. When does it stop it itching?

Scabies. A diagnosis of scabies can be clinical(observation) or by a skin scraping (microscope). If you are not improved after 3 weeks, you should have a scraping done. Most scabies does continue to itch even after treatment for about a week or two. Either this is the wrong diagnosis or treatment has failed. Scabies can be hard to get rid of.
Scabies. There is an oral treatment that I have started giving my patients given how poorly Permethrin appears to work now a days. I no longer prescribe the Permethrin cream.
Go back to Doc. Make sure all sheets and bedding have be washed thoroughly in hot water; try otc antihistamines; keep the skin moisturized; it all else fails call or visit your doctor for a prescription strength anti-itch medication or a different scabicide such as Ivermectin oral.