I appreciate your concern.
you have not mentioned the condition why doctor has told you to stop breastfeeding
,there are only few contraindication to breastfeeding and they are,if mother is HIV
positive,is having untreated tuberculosis
,is on certain medication.
There are some condition in which breast feeding is only temporarily stopped and those are any infection ans lesions on breast like boil,impetigo
or herpes simplex
.in which mother is advised to use pump to express milk which can be given to baby,
so my suggestion is that you should consult your doctor.
regarding feeding breast milk is the best milk and if in any condition you have to give formula temporarily give it with spoon,avoid bottle,
Relax your baby will be fine,