I'm around 700 too. I'm not too concerned about the score and am more focused on just having fun. I love learning new tactics from puzzles and tutorials and then try them on an actual game even if i end up losing.
I'm saying this because maybe you need to have a different outlook. Maybe play for fun instead of just focusing in climbing ranks just for the sake of it. I don't know if this resonates with you, but at least it worked for me.
My score is sinking, I might not even be able to hold the 700 points.
My games are a disaster.
I am strangely pretty ok with puzzles and I've manage to defeat all the intermediate PC opponents, but I keep making huge mistakes during relevant games. And the more I play the worse it is.
A bit frustrating.
In your last twelve games, you won 5 of them and lost 7. What disaster?