Prayer is a mystery; it’s not like withdrawing money from an ATM. Sometimes it’s working when you think it isn’t, and vice versa.
It’s better to use prayer as a means to connect your heart with God, and express yourself to Him, than treating it like God’s IT department.
Prayer is like that feeling you get in the midst of a gorgeous moment when you say to yourself, “I wish this would never end.” The fact that it does end is part of what made it special; it’s not a failure of the wish.