shrimp101--patience, patience, give us time to respond...
One thing you will learn in this hobby is that all you can do as an aquarist is provide an optimum environment for whatever livestock you decide to keep. You can give them care. But you cannot always keep them alive in spite of it.
I have been in this hobby for over 5 years, and even this year, I've lost some livestock. One of my fishes--pruple tilefish--jumped out of the tank and I found him curled up on the floor. A powder blue tang I bought died after 2 days--he wouldn't eat, and was really scared by the other fish--I found him floating two days later. A fairy wrasse I added just disappeared, and I have no idea what happened--I never even found his carcass--it was probably eaten by my cleanup crew. I added a small red reef star and he just disappeared.
Your clownfish died, and who knows why. If your aquarium is a good environment--low nitrates, fully cycled, etc.--and you didn't starve him--well, who knows why he died. He may have been sick when you bought him, overstressed from shipment, starved before you bought him, there are dozens of reasons why he might have died.
The fact is that any time you add livestock to your tank, there are no guarantees, no matter how long you've been in this hobby or how good your tank is. All you can do is provide the best care and environment possible. The rest is up to nature. It doesn't always work out.
The only other thing I'd add is know what you are buying and make good livestock choices. In my case, I shouldn't have bought the tilefish--because everything I've read says they always jump within 6 weeks. For some reason I had the delusion that it wouldn't happen to me. But it did. That was a poor livestock choice. Powder blue tangs almost never survive in captivity. Once again--poor livestock choice.
So, make good livestock choices, provide the best environment and care that you can, and hope for the best.