Thanks to everyone for the clarification and the info. To answer your question, yes, this person did bring this up in conversation (the subject of religion came up after this individual spied me with a big cup full of Starbucks). At the time, I knew even less about the LDS faith than I do now, but I still could not believe that this was actual official belief of any faith. I just could not swallow the idea that ANY religious group would single out another and say that they, specifically, would be punished for eternity for their beliefs. It just seems so hateful. I think that is totally different from thinking that one's church is the only true church. No big surprise that Mormons think this, because the vast majority of religions think this, including Catholics.
So even though I prefer to be a Catholic and feel that it is best for me, I think that even in the event that the LDS faith is the one true faith, I will still be ok. I believe in a loving God who will not look at me and say that I worshiped him incorrectly, and therefore must pay. I think he would give me credit for trying.
I told this to the person who said these things to me, and she laughed. She said I was foolish and that was just not how it worked. She said being Catholic, in and of itself, was a direct rejection of God and that unless Catholics repent for having been Catholic in the first place, they will not go to any of the 3 kingdoms of heaven. I decided to challenge this person, so I asked if she thought that Mother Theresa, a woman who lived a life of service and prayer and obedience and love of God, went to hell after she died. She told me that she most definitely thought Mother Theresa was in hell because it is unlikely that she would have renounced Catholicism after death because she was "very Catholic." It was then that I decided to just never talk about religion with this person again. I'm not the type to get into a fight. So instead of taking the word of people like her, I decided to learn about what your faith ACTUALLY teaches. So here I am. Thanks again, guys.