How can I save my Venus Flytrap? ?

I bought a Venus Flytrap after looking up how to take care of it. I got it from my local garden center. I was appalled to hear that they only water them once a week and gave them 4 hours of sun a week. My plant looks sickly and droops over. The traps closed while I was removing it from its cheap little plastic box. It has 7 traps and they are all pretty small. The pot is plastic and is a draining pot. One of the traps has closed on a small gnat and its like suctioned on the bug. Is that normal? On that traps leaves it is browning. I didn't want to shock it, so I've kept it in the mulch type stuff it came in for fear of it dying. Its obvious my plant is very weakened. I've been giving it water. At first I got spring water but I recently read that they could be harmed by it. Is Dasani bottled water okay? At least until I get some distilled water for it. I'm afraid of putting it the sun for too long because of its mistreatment with no sun. I've kept it watered, but not too much. And about an hour of sunlight. The pot it came in is small sized as in, the length of your palm. Is that too small? I'm very interested in saving my plant. I've had it for a day and I'm quite worried about its health. Its been fed one fly. The second fly it tried to eat got away because it took over a minute to close. Basically, I want to know how to build up the health of my VF. It has 3 more sprouts coming in and I want them to be healthy. I would like to know about watering it since its weakened, amount of sunlight, and repotting with some sphagnum moss and perilite. Thanks!