Steampuck: frame rate

for some unknown reason the games frame rate has decreased to almost 4 frames a second the game had usually been running at about 12 frames a second this was still bad but I was gradually increasing it to on average of 30 frames a second but for some reason as I just said  it is now down to around four frames a second I have run occlusion culling and added a fog and will now attempt to decrease the render distance in order to hopefully save more memory at the moment the game is running with a ridiculous amount draw calls I may need to do some serious editing  in order to get the frame rate to a reasonable level in order for the environment to be playable as running at four frames a second is so glitchy it makes the game almost unplayable this will have to be my main focus of the last couple of days on the other hand sealing off of the environment and re-texturing is pretty much done anything now that is on my mind is setting up the oculus rift side of the game and getting the frame rate sorted.