as you're aware, making a starter is certainly advisable, but not absolutely necessary. you obviously got fermentation, but not enough to lower to target fg. take home lesson.... make starters in the future. on the dry yeast, as mentioned there have been a couple of recalls recently. certainly possible you got a bad sachet, thus no surprise on it not helping.
you mention using Zephyr Hills water..... are you using their spring water or their distilled? There are a number of things that can limit fermentations. minerals are certainly one, and if you're using distilled (probably not, but....) then that could be an issue. certainly more of an issue with an extract batch than with all grain.
your higher temps would lead to a faster, more complete fermentation, but also one with potential off flavors - but that's not the source of this particular problem. for the future, it is possible to get cooler ferm temps without a dedicated brewing fridge. put the fermenter in a large tub of water. fill two gallon jugs about 3/4 full and put in your freezer. put one in the tub in the morning when you go to work, swap it out for the other when you get home in the evening. low tech but effective temp control. given your ambient temps, you may not get as low as you like, but should help considerably.