Establishing a tank is the most difficult part. Right now there are a few things going on with your tank:
Water quality is poor. I know it doesn't seem like much to have an ammonia problem, but unfortunately to your fish it's a big deal. That ammonia problem is, indirectly, why your water is cloudy, and, directly, why your fish are dying and have caught ich. When the water has ammonia, all of the fish have much lower natural defenses and immune systems.
Adding ich medication can help, but can also make things worse. I would stop with the medication if I were you. If you want to try to save the tank, try this:
Slowly increase the temperature up to 86 degrees F. Try for 2-3 degrees a day. This will make the ich speed up its life cycle and die off more quickly.
Since you are having ammonia problems, do 25-40% water changes every day (I know it sounds like a lot but your fish are going through a really tough time right now!). This is where your personal discretion is important, because the clean water will help the fish, but the bigger the water change, the more stressful to the fish. So if they are looking like they have one foot in the grave, try a 25% water change. If they perk right up, and are in better shape the next day, change more water. Just be careful to match the temperature, as any big changes right now will only stress them more.