How many fish did you start with and how much food did you feed them while they were in there?
The real high ammonia should not be being the nitrites are showing a decline. That excess ammonia is probably coming from all the things that are dying in there from the toxicity of the water. pH should be buffered AFTER ammonia levels come down to zero otherwise you risk poisoning the tank.
It is natural for pH to go down when ammonia is present in the environment. This keeps the ammonia in a less toxic form called ammonium. A higher pH value will release this seal and the toxin then turns back to the deadly ammonia.
What I would suggest you do, being the tank is still fairly new is to empty it of the current water and start all over again. This time, just use the LR
as a means to kick start the nitrogen cycle and trade any fish you have for credit later.
Ammo lock is OK to use in an emergency situation, but a water change is a must after a couple of doses because...all it does is lock a seal around the ammonia molecule temporary. It does release the ammonia out from this seal. It does not remove it. Use something like Nitromax Marine as a bio aditive for marine tanks.
Do you have a protein skimmer or refugium?
Are you referring this Cycle treatment to the product Cycle, the bio additive? If so, these additives as well as the one I mentioned as well as the stress-zyme you're using are just suppliments used until the system's natural bio can establish or re establish.
Bottom line, there's a ton of ammonia in the system and may be due to too many fish in a new tank at once. Perhaps the LR
wasn't cured? Perhaps a combination of things.
We, as a people, know so much more about outer space than we do about our own oceans. This lack of knowledge can very well spell the dangers that lay in wait for us.
The oceans surely would swallow us before a rock comes down to smite the planet of it's life.