Isabellyka, you have the timeline way messed up.
The day before
Brinn died,
Formendacil revealed. He thought for sure he was going to be dead that night. That is when he picked to transmit the dream to someone.
Brinn was killed by the baddies, since they believed she really was Finrod (that is not disputed).
Formendacil came out the next day and claimed
Brinn blocked his dream, but that was merely for protection to make the wolves feel they had escaped a bullet. Brinn didn't block his dream, the dream came through clearly.
Now I really do have to go, so this will have to continue until I get back, but I will love to answer any further questions you have.