I absolutely understand my friend. I think you need to research more. My suggestion would be to hand any livestock in to a good fish store, they will give you a credit but you will be at loss. The reason i say this, eventually you will lose more livestock, it isn't about how much your pocket has been hit, it is about the life that you dream of observing and have the pleasure of looking after. Give up the livestock you have(re fish), learn about your water chemistry and research the fish you wish to keep, not all are compatible , just because they are saltwater does not mean all will get along .
No hard feelings, we have all been there, anyone that says they haven't , well...there the ones to avoid!...Just like your fish guy