What should I eat or do to make my milk thicker since it's like water & my daughter gets diarrhea…

maybe more fiber and protien

if she is exclusively breastfed then her poop should not be in solid form. it will be like water with little seedling looking things in it. Totally normal, also if by thicker you mean consistency of the milk, there is no way to make your milk thicker it's perfect the way it is for her. @elizondo.sarid