It's more unforgiving than Dark Souls, don't you think? Learning to play with an abundance of caution is part of the game. If this was one of the early dungeons with skeletons, muchrooms, and cores, your gear shouldn't be that hard to replace. Wait until you die and lose a bunch of late game stuff that you need good gear to even farm materials for and then tell me how you feel...
Anyway... I can't help you get it back, if it's gone it's gone. I'll just say, play like it's your life.