I don't believe God is testing you, or has abandoned you.
Many people have said they've not felt God's presence in their lives, myself included. When times are tough, and God knows how tough its been for you (I couldn't imagine something that awful, losing a child), it does test your faith. I've been known to go into church and shout and scream at God, because it hurts so much. But when I've finished shouting and screaming and crying, I've prayed "help me". And I keep praying "help me".
People give many reasons for Jesus dying on the cross, but the one which I can most identify with is that when it happened God suffered. And we can gain comfort, POSSIBLY from that (I do). I don't know why He suffered, and I don't know why WE suffer. I just have to trust, and its when I'm not trusting, it hurts the most.
I also take comfort from Mother Teresa, how she suffered through not feeling God for almost 40 years I think. People say she lost her faith, but I don't think she did. I think she lost her feeling of closeness to God. I'm sorry if this sounds "preachy", but I'd like to share with you part of the last thing she published before she died, knowing she felt so lost:
"Am I convinced of Christ's love for me and mine for Him? This conviction is the rock on which sanctity is built. What must we do to get this conviction? We must know Jesus, love Jesus, serve Jesus.
This knowledge will make you strong as death. We know Jesus through faith - by meditating on His Word in the Scriptures, by listening to Him speak through His Church, and through the intimate union of prayer. Believe in Jesus - trust Him with blind and absolute confidence because He is Jesus. Believe that Jesus and Jesus alone is life - and sanctity is nothing but that same Jesus intimately living in you - the same life we received at Baptism grown up and made perfect.
And to read to you again, what we heard earlier, from Ephesians ? ?you are citizens with the saints and also members of the household of God, built upon the foundation of the apostles and prophets, with Christ Jesus himself as the cornerstone. In him the whole structure is joined together and grows into a holy temple in the Lord; in whom you also are built together spiritually into a dwelling-place for God.?. We should draw on the strength that Jesus has, as our shepherd. We should turn to him, when times are difficult, to join in with others in fellowship, in fellowship with Christ, the saints and members of God?s household. Draw on our strength and faith when times were better for us, when we felt closer to God, and most of all, allow ourselves to accept God?s love for us in times of trial as well as in times of good."
God bless you, and reveal Himself to you, in comfort.