You have to drink a lot of milk to produce more milk

This is not true. Any type of food and fluid taken by the mother in adequate quantity is sufficient to produce enough milk. The production and quality of breast milk is not dependent on the milk intake of the mother. The baby's suckling on the breast is the key factor and more suckling makes more milk.
 
Small breasts will not produce enough

Being able to breastfeed successfully does not depend on the size of the breast. The size of the breast depends upon the amount of the fatty tissue layer under the skin. Breast milk is produced by special glands in the breast that are present in all women.
 
You have to stop eating certain foods during breastfeeding

No, the mother can continue eating most of her favourite foods during breastfeeding. If the mother is worried about a particular food, she should eat a small amount each time and see if it causes any problem to the baby. If it bothers the baby every time she eats it, she may consider avoiding that food.
 
I was not able to breastfeed the earlier baby - and I won't be able to breastfeed successfully even this time

The mother can be successful in breastfeeding the baby even if she was not able to breastfeed the earlier baby. Confidence is important.