My breast became so soft how to know weather milk is there or not. Or is it sufficient for my baby. Please suggest me. And in middle my breast is paining too

All that doesn't determines your milk supply, if your baby is sleeping atleast for an hour after feed and is not always cranky and crying then you are good to go.

Breastfeeding Basics: How Much And When;
Also if there is pain that mean u need to express it or nurse ur baby well. Massage urself on the breast also as it may lead to lumps.