I'm so sorry for your loss. I know how you feel. I had almost same incident earlier this year, forgot to plug my heater back after doing water change. Found out about it the next day, but water was already too cold. 21 clown loach ended up with ick, and die off in the next few days. I lost the entired tank, including 21 clown loach, plus a few other fish. I stil haven't bought a single loach since then, although I still have some other loach in other tank. Hope you get over the ill feeling soon.