In my 3rd LD ( 
) I was fighting with a monster to rescue my brother, but when i realized that i was dreaming the monster disappeared 
and I couldn’t continue with the storyline 
If you have sufficient control of the dream, wish it to re-appear again. Or simply ask your dream out loud: “I want the monster to appear again!” etc.
Don’t worry about chronology. Quite frankly dreams don’t always work like WL, so don’t treat them that way. Just write down whatever you remember, in whatever time you remember it happening. When i get stumped by this i simply use transition words like “Then” or “Next” or “Suddenly…” and then write down whatever i can remember.
I guess I should practice more. 
Thanks.
The monster disappeared, you say? Maybe that’s just what it wants you to think… 
If you ever find yourself in a completely white room, do not invoke a bear!
Even when flinging it through a door won’t save you from it!
…
Yeah… invoke it through an open door, always works for me ^^