Hi dan, After reading your first post, and how the tank went 2 months with no ammonia source, I don't think your tank is cycled.
In a cycled tank, you should be showing at least some nitrates.
The 2nd nitrate bottle really needs to be shaken and banged on table and otherwise abused to get it mixed correctly.
Since you have a fish in the tank, you should do a
water change now and continue that daily until you have 0 on both ammonia and nitrites and nitrates of 5-10 (even 20, but that's on the high side)
I hope the little guy make it, if not, please continue your cycle fishless by feeding the tank with a source of ammonia (fish food, 100% pure ammonia) until your readings are as stated above.
Your fish can usually adjust to your ph.
Good luck with your tank.