In our everyday language, the term 'overwhelmed' is often used in a positive sense. You are surprised, far beyond what you could have imagined or imagined, and therefore perhaps speechless or simply utterly grateful. Overwhelmed in the real sense means that something or someone has defeated you, overpowered you. You have lost a battle, so to speak, or you have had to surrender, realise that something or someone is stronger. This is then expressed in the corresponding feelings at such moments. More than you expected, more than you hoped for, more than you can imagine. It doesn't happen very often, especially to very rational people. This is what Advent and Christmas are about. For a young couple, Joseph and Mary, a visit from an angel was overwhelming at first, but so were many other things that followed. Despite the overwhelm and the fear, there was always the protecting hand of God.
I wish you an extraordinary day!