I had almost the exact same problems as you. I finally started a new hood with out terrain paints and i rolled back my Nvidia drivers to version 77 (?) or so.... Went through my CC and took out any files that didn't make sense. I found a bed file that was 35mb's. I didn't use any lots that were created before GLS or OFB... I think over time just bad CC creeps in and enough of it causes the graphics problems.
If you can ever see the hood properly again, carefully look at the lots from the hood view and see if you can see any flashing blue things on a lot... like trees or benches, etc...
Hope this helps and good luck