I' sorry you're having such a difficult time with your furbaby. Have you looked at The Honest Kitchen? It's a dehydrated raw. If you opt for lower protein, you're going to have higher carbs, there's no getting around that. But the type of carbs can make a huge difference. They make several different varities ranging from 21% protein which is this one:
http://www.thehonestkitchen.com/products/force/
to over 35% which is this one:
http://www.thehonestkitchen.com/products/zeal/
The one I feed is a base mix of veggies/fruits and you add your own protein, which is really good for dogs who have food allergies/intolerances like my boy:
http://www.thehonestkitchen.com/products/preference/
It's a very healthy food with no fillers or artificial anything. It uses antibiotic and hormone free free proteins and organic/free trade fruits/veggies. It's a bit expensive, but it can save you money in the long run on vet bills. One thing you will notice is that they "poo" more often. I discussed this with my holistic vet and he isn't concerned. He said it's due to a high fibre content and isn't a bad thing. It's also very easy... you just add water and let it set for about 5-10 minutes to rehydrate, then feed
Good luck with your boy!!