Who sings the song I need you in my life.. So don't let me don't let me...
I can't remember the rest of the words!

Try "Don't let me down" by The Chainsmokers. The Chainsmokers - Don't Let Me Down Lyrics | MetroLyrics (http://www.metrolyrics.com/dont-let-me-down-lyrics-the-chainsmokers.html)

If this isn't it, maybe it will help you remember more and we can narrow the possibilities.