Fleas

We just found fleas on my one dog yesterday. We gave her a flea bath and cleaned the house. We haven’t found anymore on her this morning. But she isn’t eating and acting strange like she’s scared or tired. She’s usually very spunky so it’s unusual for her. We called the vet and they have an appointment on Monday but they are going to see if they can squeeze her in this weekend so we are waiting to hear back from them. But has anyone had their dogs have fleas and act weird like this before? I’m scared if it’s something serious, or if it’s just from her getting bit by the fleas?