Very symbolic dream! I used to have dreams of tidal waves also. That usually indicates something big coming or sometimes burdens that are too much for you.

the doorway is symbolic of an opportunity, the kids are symbolic of your inner child and to see your dad in a dream is looking out for you.

as scary as this dream may feel, I think that it is actually good! I have a feeling some things will be coming in fast and furious for you and you will feel "flooded "at times but you will do just fine. Have trust in yourself