colicky breastfed baby

Hey girls! So I am exclusively breast feeding & occasionally little lady will have a bottle of expressed with her daddy or grandma. From the end of week one she was screaming at the exact same time of night for about 4/5 hours at a time & then 2am on the dot every night she would stop & pass out, perfect example of colic. You wouldn't hear a peep out of her all day & then a completely different baby will wake up from her nap! We give her infacol before every feed & this seems to have cut the screaming down from 4/5 hours per night to 2 hours max & some nights she will give us a break & not do it at all! That was until last night. She is nearly 6 weeks old & it seems to be getting much worse. I'm considering trying gripe water today as I've heard it's amazing. Has anyone else got a colicky breast fed baby & if so any tips?