help with search for elise

hi,
my problem in this quest is a bit furious.
i've found the twin falls or whatever, went through all the rooms, and came to the boss. it was a great fight with him, and in the same second as he has had to pay with his life, link died also. i thought it would be no problem to come back into this room, grab my heart, then the triforce-piece.
but it is a problem. if i went again through the rooms and wanted enter the boss-room, the door was closing for my eyes. i can see the heart(i killed the boss, yeah) but i cant reach it. that means, i cant come to the triforce(if there is a piece of it in this level). that means, nothing changes in the town, that means i am fucked of. ok, i've got the flippers, but will i miss something else except that heart later on?
do i have to start again?
can someone help me please?

is that the Zora domain?
or level 5?
if it's the zora domain, go back and get the flippers from the Prince of the Zora, and don't worry about the rest, it's only a heart container "piece" and it's not a triforce level.
I assume it's the Zora domain by your post.

I set it up that way because after you beat the zora king you go out and then over a waterfall while riding the raft, the waterfall didn't want to work right the second time through due to limitations with the program.

it was zora domain. thanx a lot.