Bug with random game lag/graphical issues since 1.9 release

Every since 1.9 released, I experience lag on my computer only when opening Minecraft. Even games that are more challenging on a laptop run smooth. typical gameplay on MC is 2FPS. I don't know if this is a bug or not, but it feels like it is. i've spent a lot of time looking for a solution but have been unsuccessful. i also experience random flashing on my MC window when playing, which ultimately results in a crash. I hope this report was at least the slightest bit helpful. -GPU Nvidia, I'm using Java 9, and i have 2GB Vram