7 week old not feeding much

Sri • Mom to beautiful girl 06-24-19

My baby is 7 weeks and has not been feeding her normal amount. She usually chows down about 3 to 3.5 ounces but now she barely takes 2 ounces and sleeps for three to four hours. She feeds fine at night but during day she cries, pushes away the bottle and screams till we stop feeding her. We had to switch formula cuz she has been very gassy and has reflux. But her reflux has gotten a bit better but she gets very gassy and is in pain. We tried different formulas enfamil, similac sensitive, similac spit up, alimentum and now similac pro advance but nothing seems to work. She did fine with alimentum but refused to feed cuz of taste maybe. I don't know what to do. I heard about silent reflux but I am not sure if that's what she has. I am just so worried about her and I am at verge of losing my shit.