Possible inadequate system requirements?

So I have pics if they are needed, but here’s a simple explanation.

I use a gtx 770 overclocked and 12 gigs of ram…im honestly not sure what else is important.

I have a HUGE map. huge…I’ve built and built and built on it. Mad foliage and tons of models and for the longest time I’ve ran it very very smooth with no issues. I have finally come across a problem and I’m wondering if I’ve done something wrong or if There is something I need for my PC.

I just finished adding a TON of more foliage. Anyways…Now when I go to build the lighting…nothing happens…and also When I go to play or simulate the game, The foliage all has a bright glow like it has it’s own specular light applied…different colors extremely bright and random. . It seems to me I’ve overdid something by a long shot. The map is definitely jacking up when I play…but as for my frame rate it’s decently solid.

Could anyone tell me if they’ve had the same issue?? and when comes to large scale maps…Do I need to double my RAM to help with processing the models??
I’m basically just trying to figure out how I’ve done what I’ve done…and how I can refrain from doing it again…and if I need more power in my PC or not.

I have pics if needed…thank you everyone.