Quote: "well it worked but the game now takes almost double the time to load and started lagging"
Static lights shouldn't affect the performance when you're
in-game, but yes, it will take longer for the engine to calculate lightmaps when you raise their quality.
Quote: "no way I can make an object not affected by lights?"
Not that I know of. But if you set your terrain to dynamic, it will smooth out its surface faces, and will no longer receive highlights and shadows from the lighting in the level. You can then bake your own ambient occlusion onto the terrain's texture in the modeling program so it doesn't stand out from the rest of the models in your game.
Kravenwolf