It sounds like you do Joanna. First of welcome to AC. This is the wrong forum for this so hopefully someone will move it for you. There are lots of reasons fish die. For us to help you, you need to supply lots more info. We need to know, tank size, type of fish, did you cycle the tank, how long has tank been set up, temperature, and absolutly everything else you can think of. If you have the numbers for all the normal tests they would also be helpful. I doubt you have any of these numbers though so give us everything else and we will go from there. Do not get discouraged as you can keep fish but it will take a little work, time and patience.