Can my paycheck legally be garnished if I have a disabled child?

I have a disabled child who is on SSI and my work paycheck is being garnished. My daughter is on a GFCF food restriction diet and it affects her health greatly because she is allergic to the gluten and casein in foods and since I have been garnished, I have had to take her off of the diet. The diet costs about $300.00 a week to keep her on it. Since she has been off of the diet, it is affecting her health greatly. I cannot save up the funds nor borrow the funds to file a bankruptcy. So, I was wondering if there is anything I can do to get this garnishment off me? I have another garnishment waiting in line. My child has multiple disabilities and the bills have just added up and slow pay does not help.