When I'm breastfeeding do I still have to follow the same food regimen as when I was pregnant?

No. You have more freedom while breastfeeding. You can have alcohol for instance. You want to make sure the food you eat won't make you sick though. Wash your fruits and vegetables thoroughly. Your meat and fish should be fresh.
Almost. You need about 500 calories more a day while breastfeeding, at the end of the pregnancy this was 300 calories. Fluids also help with mild production.