Nick,
Did the priest say the words of Consecration and forget to lift the chalice and host? Or did he skip that part of the Eucharistic prayer altogether?
For the Consecration to be valid, it needs all three elements: valid matter, valid form and valid intent. If you believe that he intended to consecrate but didn’t say the words, then I don’t think it is a valid consecration. Form would be missing. On the other hand, he may have said the words inaudibly and the consecration would be perfectly valid.
The one issue where you may have gone wrong was “approaching Communion as if I were receiving merely bread and wine”. Catholics don’t profess a purely symbollic Eucharist. So if you truly believed (at the time) that there was no valid Consecration, you should have refrained from receiving Communion, IMHO. In fact, I don’t understand why you would want to go to Communion if you didn’t think it was valid?
As far as Confession, how about “I willfully received what I believed to be non-consecrated elements at Communion - one time”? If your confessor needs more info, he will ask. There isn’t any reason to get into what the elderly priest did or didn’t do unless he (your Confessor) needs that information to understand the situation.
