war on diaper rash 😡😡

After another trip to the store I am at my wits end. My LO is three and half weeks old and has had a spot of diaper rash I can't get to go away. I give her diaper free time ,rinse her butt with baking soda and water twice a day in case of acidic poop, I have tried different creams such as triple paste A&D ointment Aquaphor vaseline Desitin and butt paste. I have even tried coconut oil and have started making our own diaper wipes. The rash looks like several raw spots not blisters or rash. I feel like a terrible mother  and am irritated that nothing is working and I have spent a ton of money on products that are doing nothing. Her pedi told me to use A&D but that seemed to make it worse.