Yeah, you can and should fix your LG performance.

I started with Barron's Logic Games. It was a fantastic introduction that helped me to understand how the games broadly work, and I don't think I would do as well with the games as I do if I hadn't started there. But I would never use their diagramming methods on the real exam- they're way too time-consuming, they take up way too much space, and they're inflexible and don't work for many of the games. More importantly, the book only covers the simple, easy games. If I'd gone through that book and then expected to do well on LG on the LSAT I'd have been sorely disappointed. But I think the easy introduction laid a critical foundation for me and I don't regret buying it.

Games as they appear on the exam didn't click for me until I started going through the PowerScore LG Bible. Again, I don't think the PS LGB would have helped so much if I hadn't had the introduction from Barron's first. Once I went through the LGB and started with PTs, games clicked for me (to a consistent -1 or -0) after four or five PTs, so maybe 18 games? I didn't start timing myself until the games clicked. I don't think it's helpful to put yourself under time stress when you haven't nailed down the concepts yet. Figure out how to do it at your own pace- treat it like an actual game you're doing for fun; a crossword or a sudoku puzzle- before you try to speed up.

Reviewing 7Sage's video explanations helped a lot with the ones that were still tricky. Sometimes I still struggle a little with the weird games but regular practice is smoothing it out.

It's a steep learning curve and I think you just have to power through it.