Anyone here consistently in Diamond as a Roach Forest player?

I've played roughly ~260 games as Forest and I'm constantly bouncing between Ruby and Sapphire. I actually feel like I'm worse than I was a week ago. I thought I was a smart cookie but I've been humbled by a children's card game. I'm sure I'm making retarded decisions but I don't know how to learn, cause just spamming more games isn't working.

Help? Tips? Ways to improve? I can't swap my brain for a bigger one