baby cries at night

Anyone else's October baby (almost 4 months old) cry every single night before bedtime? I have no idea what it is! She's changed, fed, and burped. She has eczema so her skin is really dry and red so we moisturize her often and before bed. We have a routine. She just cries for like an hour before finally getting exhausted and falling asleep. I feel so bad but don't know what to do!