What to say if you are afraid to go to sleep or feel lonely and depressed

‘‘I seek refuge in the Perfect Words of Allah from His anger and His punishment, from the evil of His slaves and from the taunts of devils and from their presence.”

 [Narrated by Abu Dawud 4/12 & Sahih At-Tirmidhi 3/171]

What to say before Sleeping

"If one of you rises from his bed and then returns to it he should dust it with the edge of his garment three times for he does not know what has occurred in his absence and when he lies down he should say:

“With Your Name my Lord, I lay myself down; and with Your Name I rise. And if my soul You take, have mercy on it, and if You send it back protect it as You protect your righteous slaves.””

[Narrated by  Al-Bukhari 11/126 and Muslim 4/2084]