Amen
You need to confess your sins to a priest in the sacrament of reconciliation
When the priest says 'the Body of Christ' or 'the Blood of Christ' the person should respond with 'Amen' signifying that he or she believes that the bread and wine are truly the Body and Blood of Christ. If you cannot honestly respond 'Amen' then you have no business receiving communion.
A priest's ability to consecrate and celebrate the Eucharist is provided to him in his priestly Faculties. This faculty is not impaired or removed simply because the priest is a sinner. In fact it would be a miracle if there were a Catholic Priest anywhere who was not a sinner. So there is nothing wrong, different, or missing in a communion service that is led by a priest who has sinned. You should be able to take communion from this priest in full confidence that it is properly consecrated. Should you take communion? Is a somewhat personal decision. The Catholic Church recommends that as long as the priest still has his faculty to celebrate mass, that you should feel comfortable participating in the mass and receiving communion.
Only God can heal you from sin, and will do so if you are truly sorry without seeing a priest; but you should then see a priest fpr the sacrament of reconciliation before receiving communion.
Roman Catholic AnswerOne may only receive Holy Communion when one is in a state of grace. Receiving Holy Communion in a state of sin is a grave sacrilege and another mortal sin. If one is the innocent party to a divorce, has not attempted a "remarriage", has been to confession, and is in a state of grace, then there is no problem with receiving Holy Communion. If in doubt as to your status, check with the priest while you are in confession.
Your response is "Amen" as you bow your head slightly; same as receiving the precious bread
The priest gives the bread during communion
Traditionally only communicants (those receiving communion) should process and present themselves to the Priest or Eucharistic Minister. Sometimes those not eligible to receive communion process and they cross their arms to signify that they should not be offered communion. If a priest is distributing communion they may say a quick blessing on the person. This started when parents did not want to leave young children in the pews and so brought them forward. Most churches prefer that only communicants process as this speeds up communion.
You need to be baptized Catholic, and have made your first Holy Communion, you need to be in a state of grace, otherwise, you need to go to confession before receiving Holy Communion. You must be fasting for one hour prior to receiving Holy Communion. If divorced, you need to get an annulment before attempting marriage again. If married, you need to be married before a Catholic priest, or dispensed from such by your Bishop.
Roman Catholic AnswerThe only times that a Catholic Church would have a Communion service would be if a priest were not available. In my diocese the rules are that a parish may have a Communion service on one Sunday out of the year if it is impossible to get a priest. The Vatican forbids Communion services during the week, and on a regular basis. There had to have been a priest there before the Communion service to consecrate the Sacred Hosts.
Catholic AnswerNo, the Prayer after Holy Communion is in the Missal. The Communion "reflection" is something that the priest is making up.
Roman Catholic AnswerOnly a priest or a Bishop can confect the Eucharist.