I agree with all the others!! A few bad circumstances came together and "all H*LL broke loose!".
Believe me, I’m sure almost all of us has had casualties at one time or another for various reasons!!
Last year when I started I did great in cycling my tank, had everything running great!! I was so excited as a newbie and still got things going. BUT…. than one fish after another died. I got more, again, deaths…. it took me like 4 months and 150 dollars worth of sushi to find out it was my coral banded shrimp that was preying on my fish. Everywhere I read it said they are harmless, yeah right!! My LFS was helpful and took him back, after that no deaths…
Except for my scooter blennies…. they seemed to be starving to death. I even had one expert tell me that would always eventually happen. Til I talked to my LFS guy and he said try this.. and gave me some blood worms… I’m like, you do know this is a salt water tank… he said "trust me.." The little guy LOVES them and eats like 6-7 a feeding and has a round little belly (compared to the sunken in ones the others always had when I was feeding them shrimp). I have to be careful as to make sure the worms don’t make my water go bad. But, I take out the excess and have a huge clean up crew in the tank to get what I missed and up until now everything seems to be fine. I know a few people out there will be crinching at the thought…
Than of course my first two seahorses…… they were wild caught and I didn’t know it. Well, you probably know how that went.
My advice, yes bring back what is still alive to your LFS. Go on your trip, and when you come back take a deep breath and start again. The people on this site are great and there is sooooo much knowledge here!! They walked me through it and we’ll all walk you through it one step at a time.
You will need a bit of patience in the beginning, but believe me it is worth the wait!!
Hope you are feeling better!!