Often prayer is taught in a way that gives the impression that some have the gift of prayer and others don't. We are disappointed when we are distracted in prayer and so we give up the practice. We beat ourselves up when we are not at ease with "praying from our hearts" because we are told that praying from our hearts should come naturally.
It may be helpful to remember that within Christian spiritual practices being uncomfortable or distracted in prayer may indicate you are on a good track.
When we are uncomfortable in prayer it is because we know prayer is a vulnerable act. And being vulnerable is often uncomfortable for us. As such, if you are uncomfortable with the practice of praying it may mean that you are finally abandoning the false facade and expressing vulnerability.
Additionally, when we are distracted in prayer is means we have allowed something else to take center stage in our hearts and minds. As such, we have a chance to return to God as the center. This returning, also called repenting, is the very type of prayer that Jesus elevated in places such as Luke 18. Just as there is great rejoicing when one who is lost is found, so too there is great rejoicing when we return to God at the center or our prayer.
So if you are uncomfortable or distracted in your prayer life, the good news is you may very well be doing it right.