Why wont my 2 month old eat?

we have been to the doctors and this has been going on since she was born no one thinks its a big deal she has only gained 2 ounces since she was born. we were told she was colic but that is not all of the problem we changed formula walk her bounce her ride her around music no music shhhh for hours hold her all the time her legs draw up from cramps. then when the g pes she still cries and wont eat. the doctor told us it must be a cold gave a script for a humidifier and sent us home then we had lactations people come and nurses and health people who all dont know why. there best answer for us was your tense and need a babysitter for a couple of hours a day. but she cries and wont eat for them either i am very very worried about her