Thank you for your question, Cheryl. It is the source of confusion for many so I am very glad that you asked. Please know that the Catholic Church does recognize your Baptism into the Christian faith.
The “why can’t I receive Communion part” is the tricky piece. Let me begin by explaining that Catholics believe in the “Real Presence” of Jesus in the Eucharist, meaning that we believe that the bread and wine are changed into the actual Body and Blood of Christ. We even have a fancy name for it, Transubstantiation. This is very different from communion in Protestant churches, as they believe it is symbolic.
Another unique aspect of being Catholic is that when we receive the Eucharist, we are stating with our minds and bodies that we are in full communion with the teachings of the Catholic Church. This means that we are trying to live lives faithful to all the teachings of the Magisterium, another fancy word for the teaching office of the Catholic Church.
As we approach to receive the Eucharist, we enter into a covenant with God each time. By responding, “Amen” to the priest, we are saying that we believe that we are receiving Jesus’ actual Body and that we are in communion with His Church. If a Protestant receives the Eucharist it would be, in essence, forcing that person to swear a false oath. The Church takes covenants very seriously (look at marriage) and would rather have you not receive than force you to say something that you don’t believe.
I respect you for asking the question, Cheryl. I know that it is a source of hurt and confusion for many. I encourage all of my non-Catholic readers to ask questions. It pains me to know that many misunderstandings have led to such division among the Body of Christ. Although I make no apologies for my Catholic faith, I would love to be able to reach out to the many denominations in truth and love..and maybe start to answer some of the questions about Catholicism that you’ve always had. Keep those questions coming!