Help with sacrificing for my child!

Max
My daughter has developed rashes on her face, knees, elbows, neck and back. Recently I found blood in her stool. The doctor says she has a possible milk allergy and I've been told to cut all dairy until her next doctors visit to see if there is any improvement. 
Mothers who experience this how did you cut all dairy? I am receiving state aid while I'm on leave and WIC doesn't cover any non-dairy alternatives😩 
My question what are good alternatives to replace the dairy? My biggest issues are cheese, cereal, and yogurts. 
Also if your child went through this how long did you have to stay off dairy? I'm already really thin so now having to exclude a big part of where I get my fat from from my diet concerns me...