I've been stuck at 1100 since I started, doing puzzles everyday, playing bots, and learning some opening variations. My only advice is try playing longer games and calculate. Don't just move, calculate further ahead and look for better moves, but I don't know. I'm 1100 same problem..
A rating of 890 is a sign of frequent blunders. Always check your intended move is no blunder before you play it. That little mental discipline alone is enough to get you to 1500. Books do not help as long as you hang pieces and pawns.