Seek Jesus in prayer. Cry out to Him, he will hear you, and answer you if you mean it! Ask Christ Jesus to save you and forgive you of your sins, and wash you whiter than snow, however you must not return back to your sins. In prayer to Christ Jesus, you must repent of your ways, and decide to put Christ first. Christ will give you peace, a deep peace, and instantly the depression and the darkness will simply disappear.
REMEMBER THE WAYS THE LORD LED YOU
And you shall remember the whole way that the Lord your God has led you these forty years in the wilderness, that he might humble you, testing you to know what was in your heart, whether you would keep his commandments or not. And he humbled you and let you hunger and fed you with manna, which you did not know, nor did your fathers know, that he might make you know that man does not live by bread alone, but man lives by every word that comes from the mouth of the Lord. Deuteronomy 8:2-3 (ESV)