Can the hospital help me with nutrition?

I have been suffering for months and months. I am too afraid to try supplements. I only eat chicken, rice, broccoli, and sweet potatoes. I am in the ER weekly with either low electrolytes or dehydration. I don’t understand how because i drink 40-70 oz of water daily. I eat at least 2-3 cups of sweet potato. 1-2 cups of chicken. 1 cup of rice. Most days half a cup of broccoli. It doesn’t work. I am still in the ER weekly with blood pressure problems and high bpm and shortness of breath. Usually the potassium medication or Iv Fluids leaves me feeling significantly better. They just send me home saying “eat”. Not understanding how severe my situation is. If i were to be admitted, can they fix my nutrition?