The key is

For I know the thoughts I think toward you, says the Lord, thoughts of peace and not of evil, to give you a future and a hope. (Jeremiah 29:11 NKJV)

God doesn’t desert us in our times of disappointment. Instead, He’s there. He’s thinking good thoughts of us. He has plans for our future. He wants us to carry on with life and not give up, to have hope for what’s ahead.
 The key is to look to Him, to know that He loves and cares for us, that He will carry us into the future. We aren’t meant to stop living, to give up hope, but rather to carry on in faith and trust. He will heal. Things will change. Life will continue on, and there is hope ahead.
 It’s good to remember that there are times when something looks like a great defeat, a terrible and permanent loss, which makes you feel you can’t possibly recover it. Shattered hopes and dreams are not final destinations.
 A lot depends on how we respond to disappointments. Also, let’s not forget that God might even have some surprises up His sleeves. He may very well be working behind the scenes in ways that you don’t see or understand.
 So we simply have to trust Him, to know that He knows what He’s doing, even if we don’t. —P. Amsterdam [1]

 The Christian life is not a constant high. I have my moments of deep discouragement. I have to go to God in prayer with tears in my eyes, and say, ‘O God, forgive me,’ or ‘O God, help me.’ —Billy Graham

[1] P. Amsterdam Anchor Hope in the Face of Disappointment