Ok. so you've got probably at least another 2 weeks before the nitrates start to drop down to respectable levels.
We have the same tank..Things happen much slower in our tanks than others because of the amount of water. A 55-75g tank may cycle signifcantly faster than our tanks, just because of the water volume.
You didn't help by running out and throwing a bunch of fish in. (just being honest)...that slowed the cycle even more, and is the reason why the trigger died.
You have a few options at this point.
1. Pull all of the livestock out of the tank, take it back to the store for credit. (you're gonna lose your ass on it, but.....)
2. You can leave the livestock in the tank, and risk losing everything, and not getting any money back.
3. You can continually do 30g water changes every other day, just to try and keep the nitrites and nitrates to a minimum, which will cost you an arm and a leg.
Those are really your only options at this point.