My daughter is afraid of monsters

My daughter has recently come up with the idea that she is afraid of monsters in her bedroom. She is 3 years old and last night come bed time. We did our nightly routine. Get her teeth brushed , daddy read her a book and then it was time to be tucked in. But last night when it came to being tucked in , out of no where she was hysterical. She is afraid there is a werewolf under her bed. She was screaming and crying like no tomorrow. I am a first time mom, and I already find it hard to understand and help her with her emotions. My husband said to just close the door and leave her bee. But this isn’t something she does on a regular basis. She mentioned monsters on the weekend. But nothing like this. Long story short. I am worried I am being horrible by getting frustrated with it , because she may genuinely be afraid and be feeling very real emotions that myself and my husband don’t understand. And I don’t want to neglect her emotions. I don’t know how to handle it. Please help 🥰 via /r/Parenting https://ift.tt/2u2l1mO