Hi,
Just wanted to share an excerpt from jw.org
"What if feelings of unworthiness make us think that our prayers are not being heard?"
Depression may cause us to conclude that our attempts to please God are not adequate. However, our heavenly Father is sensitive to our fragile emotions, “remembering that we are dust.” (Psalm 103:14) Even if “our hearts may condemn us,” we can “persuade our hearts” that “God is greater than our hearts and knows all things.” (1 John 3:19, 20, footnote) Therefore, you can use expressions in your prayers that you glean from such Bible passages as Psalm 9:9, 10; 10:12, 14, 17; and 25:17.
Hope this somehow helps. :D