My 8 month old twins slept perfectly from 3-6 months. They were doing up to 12 hours per night and it was amazing. But about 6 weeks ago they started waking multiple times throughout the night. Tonight I've been up about 10 times. They will go back to sleep after a few minutes if I hold their hands, but just wake up again 10 minutes to half an hour later. I don't really know how to deal with this as they were always so easy before... I'm using white noise but that doesn't seem to be helpful. Does anyone have any advice please? I am so tired 