I have been making cheese at home since childhood. Currently, I make homemade mozzarella at least once a week and use regular whole milk right off the shelf from the market, store, etc. There is no need for "specialized" milk. We have also used the goat's milk.
Making cheddar at home is a bit much, needing more and different equipment, curing area, etc.
The best water to use is spring water or distilled. The Dasani you used does have the added minerals and is not a good choice, as you found out!
The key to making cheese, however, is to keep at it, just like everything else in cooking and baking! Practice, practice, practice, as practice makes perfect! Don't give up so easily because when you do get this down pat, you'll never want to go back to store bought!
Also, make sure you have all the proper equipment, including a thermometer. Achieving the proper temperature is so critical, just like using yeast. If the liquid is too hot or too cold, the yeast will be damaged. Same holds true in cheese making with the rennet, mesophilic starter, etc. And it IS fun to make!!!