I got stuck at 600-700 elo on chess.com in rapid

I have been playing chess from over a year now and I want to get to 1000 elo. Highest I achieved is 800 but then I fell down to like 650. How can I get to 1000?

One thing I noticed that I can only usually win games when I have material advantage in endgame. If materials are equal, I either lose or draw.