My Twin sister's baby of two weeks old has not been feeding well, sleeps a lot, and toss almost every time making sounds as if she's not comfortable.
The baby is experiencing colic. Colic is common in babies. Unfortunately, there are no proven treatments that consistently help every baby.

It usually starts a few weeks after birth and often improves by age 3 months. By ages 4 to 5 months, the majority of babies with colic have improved.