u/Tough-Chipmunk-370

I spent years finding a moisturizer that worked perfectly for my sensitive skin. Didn't break me out, didn't irritate my rosacea, felt amazing, absorbed perfectly. Finally found "the one" after wasting hundreds on products that didn't work. And they discontinued it. No warning. Just gone from the shelves and the website. I have one bottle of Avene Tolerance extreme cream left and I'm rationing it like it's the apocalypse. I've been trying to find a replacement but everything I try either breaks me out or irritates my skin. I'm right back to square one after years of searching.
How do you find a replacement when you don't even fully know why the original worked so well? I just know it DID.