I wanted to save little dog that felt into the water, a river. I was standing at the side of the river. At that moment a huge whale appeared, wanting to swallow me. I struggled hard with its teeth to avoid being eaten. I was frightened but I woke up.
Good morning, Emma.
I notice that you said you wanted to help the little dog, but you did not go into the water -- you only stood at the side. It's possible that the whale, then, represents guilt over some past inaction. You're being "consumed" by guilt because you denied some small favor, represented by the dog. What the dream seems to be saying is, the guilt is completely out of proportion. Forgive yourself and resolve to do better next time.