Roberta C. Bondi in her book To Pray & to Love: Conversations on Prayer with the Early Church has the following quote from an early Christian desert father (pg. 7):
Abba Macarius was asked, “How should one pray?” The old man said, “There is no need at all to make long discourses; it is enough to stretch out one’s hands and say, ‘Lord, as you will, and as you know, have mercy.’ And if the conflict grows fierce say, ‘Lord, help!’ [God] knows very well what we need and [God] shews us…mercy.
Right now many of my prayers are simply, “God!” or “Ohhh, God!” When it is bad these words repeat over and over again – not b/c I want to vainly repeat the same words – but b/c it is all I feel the strength to say.