Having lost fish before, I can totally sympathize.. now to address the question of what to do with your Molly fry, that would depend on if you want to raise them.. leaving live-bearer fry in a tank with their parents is almost a certain guarantee of the majority, if not all of them, being eaten.
Within the last year or two, I started taking an active interest in raising my Molly Fry, so I set up an extra 4gal. tank with a couple of small coral-type ornaments and a long flowing bushy type artificial seaplant. I would then monitor my pregnant females whenever I could, and the moment I noticed them looking as if they went 'Jenny Craig' on me and lost a lot of weight, I'd start searching carefully and gently through the plants in that tank with a Brine-Shrimp net until I find the fry, and transfer them gently over to what I've now taken to calling my Fry-Tank.
As a result of doing that separation of fry and adults, and feeding them 'First Bites' powdered food for their first couple of months, and then alternating between Brine-Shrimp, crushed flakes and First Bites, I've raised several batches of healthy Molly, Platty and Swordtail fry and have given many away to various friends and sold some to
LFS.
My main tank now has a full mix of some of the finest Dalmatian and yellow spotted Mollies, along with some of the most vividly colored Platties and Swordtails ( I keep the best for myself.. LOL), and it's an ongoing cycle since I am always moving fry over to their tank!