A couple of years ago I was at Mass in the back of the church, in one of the last pews. At the end of Mass I noticed a small white piece of something on the carpet that I thought might be a fragment of the consecrated Host. I picked up this piece from the floor and could not tell if it was a Host fragment or not. The logical part of me thought that is was just a stray piece of detritus, but the scrupulous part worried it might be a Host fragment. I was in a state of mortal sin at the time, so I did not want to consume it, and was too embarrassed by my scrupulosity to take it to a priest, so I threw it in either the grass or flower bed when I left the church. The reason I did this is that I thought from my days as an altar server that it was appropriate to either wash Host fragments down the sancrium (thus emptying onto the ground) or to bury such fragments (I now know that these actions are not to be done). I may have had a stray thought that I might be committing a mortal sin by not taking it to a priest, but in my very scrupulous-wracked brain I was trying to do the right thing.
After reading about sins which bring about excommunication I became worried that if it was a Host fragment or if I thought it was a Host fragment I defiled the Eucharist and brought about excommunication to myself. Do you think I committed mortal sin in this act and am now excommunicated? If so, how do I get the censure lifted? If I was on my deathbed, could just any priest hear my confession and lift the censure?