If you have ever prayed for something and you begin to see this sudden assurance within you that God has answered your prayers, then later in the day the fears comes again and you start doubting if God really heard that your prayer you prayed. There are things you must know about such situations of it has happened to you.
Are you aware that the doubt you felt later in the day was not your mind, it was Satan whispering to your heart because he knows the doubt can shut down the manifestation of what God is doing in your life.
Genesis 3:1
NIV
After God told Adam and Eve from the tree, when Satan came He said to Eve " Are you sure this is what God really said?"
One of Satan goal is to make you doubt what God has said to you. When you begin to receive that doubt, this the time that you must rebuke the voice of the devil and begin to recite what God told you or begin to remind yourself of that assurance that you felt and in just a short time, you will begin to see the answers to your prayer manifesting in reality.
Stay Blessed.