Poor baby! I understand your pain and frustration!!
Peanut was in the same boat as Neko. I went through so many different foods, Benadryl, hydrocortisone cream, itch shampoo- you name it I tried it!
The hydrocortisone really did help for Peanut on the “hot spots” I took him to the Vet and the Vet gave him the cream, and Benadryl pills. The Vet also sent home some "neopolydex" that really helped those spots clear up as well.
This shampoo I found at Petco, helped a little too.
petco.com - SentryHC Dermasphere Anti-Itch Dog Shampoo customer reviews - product reviews - read top consumer ratings
I would highly recommend taking your into the Vet see what he says- he can send home some meds to help him in the meantime. I would also look into a different food. I highly recommend CC, Peanut is on CC and he is doing great! He went from an hot spot biting his leg hairs off itchy red mess, to a perfectly pink tummy, no itchy, no hot spot baby! He loves the food too!!
Theresa (RileyDC) recommend the food to us and I gave it a try, I thought to myself It can’t get any worse!! I’m so glad I did!! I know a couple other YT’ers were having the same issues with their babies, they have tried CC and have seen a difference in a week’s worth of feeding~ It might work for Neko, and it might not, but to me it would be worth the try!!
Whatever you decide, I hope you find something that helps your baby!!