Dry straw like hair?

Been ttc for a few minths now and taking prenatal while i do
​I thought my hair woyld be amazing!
 
​But my hair is like straw.. Its crunchy.  Its itchy.  Its dull. Its stiff.
​My nails are really brittle too??  
​Do u think something is imbalanced?
​Ive tried new shampoo..with no alcohol.. Hair masks.. Etc
​Nothings working