Welcome Mitch. Juniper show their health after the fact. Any conifer is probably not the tree I'd recommend to a first-time grower, because of their having health changes months before they show them. Your tree may well be unwell beyond any hope of salvage.
Learn how to use a wooden splinter or chop-stick to test for need of water. keep on the north exposure and cross your fingers.
FWIW I am not a superthrive booster, but I doubt if that is the only thing affecting your tree.