First of all, welcome to the board and my sympathies for your problems.
Please don't take offense to what people are saying here, they're merely stating facts and their experiences in an effort to help you.
Also note that fish stores in general have a somewhat poor reputation on this board. Sure, there are plenty of good ones, but probably every member of this board has some LFS horror story as the stores are in a business to sell things, and sometimes they and/or their employees aren't as experienced as necessary. I've read of advice/information/products dispensed from fish stores that even with my limited knowledge, I know just aren't right . . . people being sold fish for tanks that in no way are seasoned enough or big enough . . . snake-oil treatments . . . improper equipment for the goals of the hobbiest . . . quick-result products that do more harm than good . . . that sort of thing.
As some of the responses have mentioned, very specific information must be provided . . . not just "It's good" but exact numbers, species, equipment, etc. There are so many factors that have to be right on for a tank to work, and it helps tremendously if every variable is known.
Lastly, please remember that one, this hobby entails replicating in a closed environment a very specialized habitat that requires careful attention . . . two, the tank-keeper is a custodian and caretaker of some very fragile and unusual specimens that shouldn't be frivilously bought and/or discarded.