struggling with bottle feeding

[shaz twins mum]

Hi one of my twin girls really struggles with feeding from her bottle. i have bought so many different bottles and anti-colic bottles and every different teat to go with the bottles but she still seems to gulp air with every mouthful and ends up choking and crying she has now got bad colic and i have tried every medicine to help her i have even tried different milk but that still doesn't work i have tried feeding her in different positions and tried to make her as comfortable as possible but nothing is working i need help as i feel that i have tried everything that i can x