Im get really angry now

I switched from Royal Canin because Jersey (4 months old) was losing weight and they did blood work and she had very low kidney function..i thought i was going to lose her. I put her on Chicken Soup canned and she's gained weight...what the hell am i going to do now?!

i dont think there's ANY food left that's safe. I have wet and dry so i'm hoping she will eat the dry now.
what is everyone else that feeds Chicken Soup going to do now?