Since we come back from our vacation over a week ago, LO hasn't been sleeping well at night. He wakes up at least 2-3 x a night when he used to wake up once for a feeding. And when I do feed him and try to sooth him, the minute I put him back in the crib, he's wailing. Not sure what to do. We usually use the Extinction method, but it seems like he actually knows what's coming so he starts wailing louder and longer as if he's testing me. Any advice or words of encouragement? I'm tired and I thought were done with this sleep training biz.