aww puppy, dont give up, u have all the makings of a fantastic fishkeeper. when i started i was a -flippin muppet -for want of a better word-, but its does take paitence, and sadley a few losses, dont think of this a failure on your part,think of it as a learning curve, you know now that you musnt wash the filter under the tap, and that you need to do reg water changes etc, i bet if a very new member came on asking questions, you could help out, with what you have already learned, i know its been a really hard week for you, but please, please dont pack it in, keep reading, reading, and reading,
ask your dad to give you an advance on your poacket money and get a nitrite and ammonia test, this way you will always know,exactly where you are, if he wont, then do frequent water changes everyday, maybe just a few jug fulls, but its better than none at all.
you are very young and are having to take a lot of information in very quickley and i think you are wonderful for doing it,
please dont quit

lots of love
shelagh xxxxxxxxx