I use a prayer book from the Oblate Missions every day - there is a prayer in there that I say for my foster-kids' biological mom. But the other day, I happened to flip through the pages and came across these two prayers which definitely spoke to where I am right now. Perhaps you might find them helpful as well.
Prayer in Time of Loneliness
Heavenly Father, at times I feel that you have forgotten about me. When I most need You, I cannot reach You. Yet, I do believe that You are present in my distressing loneliness. Teach me to find you even in my darkest times. In the name of Jesus, the Lord. Amen.
Prayer in Time of Depression
Lord Jesus, I have doubts about myself; I feel that my faith and trust in You are weak. Stay close to me. Take my hand and lift me up and out of this depression which interferes with my life and with my peace with others. In your Holy Name, I pray. Amen.