Lactose sensitive or gassy?

I’m trying to figure out if my baby is lactose sensitive or just gassy? How can I tell the difference? She’ll be a month old on Thursday and if she’s not sleeping she’s is crying and seems so uncomfortable. We do the leg movements before almost every feed and I can usually get some gas out of her that way but her tummy is super grumbly, her poop is very watery and she just seems so stiff. Has drop do help a little but even with them she’s still pretty uncomfortable. Any advice is appreciated! I don’t Want to cut out dairy unless I really feel the need to:)