If there's just no system settings, you may try looking into mods, or learning how to manually edit the config file yourself?
It looks like for windows you can use opengl or a special launcher. I'm not sure how different it'll be for you, but seems to be a common problem so someone has likely found a solution somewhere.
Not sure if Lemmy is big enough for someone to come tell you, but whenever you figure it out maybe edit you post with the fix so this stuff can start building up here.
