It sounds like a gonner, sorry.
But, your pyto and cyclopeeze is the perfect food for clams. They will take both. 3" and under clams need to be feed. The best way to do this is to cover the clam with the top of a cut soda bottle(which is hard on rocks)or put the clam in a bowl. I do the latter. I fill the bowl half way with tank water and put the clam in it. Feed the bowl with your food and wait 20 mins. I did this last night by leaving the bowl in the water. If you tip the bowl sideways, you don't even have to lift the clam out of the water.
Then return the clam back to it's spot. Of course, you can only do this if the rock is small enough.
The soda bottle way is, cut off the bottom. Cover the clam and squirt the food in the open top. Put the cap on and wait 20 mins.
Yes, check for the tiny white snails. They look like rice. They go under the clam and eat the inside out. If you do have them, they are very hard to get out of a tank. You would have to break it all down and switch out rock and sand. I had the snail type pyramids and I did suck out all my sand and haven't seen any yet. It's only been a month so the jury is still out weather it worked or not.
HTH