Lag when playing the map?

[Draugemalf]

So I've been working on a map and noticed that when playing it in the game I have a lot of lag, around 5-10 fps. I had around 50-60 fps during the main campaign, so i guess that my hardware isn't a problem but something about the map is, which is odd. I've only added some basic corridors and walls/doors and decorated a room or two. Also this is my first map so I don't have a lot of experience with level making besides a bit of unity so there might be something obvious that I'm missing.

Here are some screenshots. This is about 60% of the whole map layout I'm planning to make.

Is there something I can do about this or do I need to split the map in more levels? If I have to do that is there a way for the game to memorize what has already been done in a level? (event triggers, object placement , doors and levers etc)

Edit: Fixed it. There were some overlapping rock entities stuck in static objects that caused a lot of lag.