1) Did you try to do a full reinstall of your game? If you use Steam -> delete local content (Steam UI, right click on game). Then delete the folder manually. Reinstall your game. Verify cache (Steam UI).
2) How is your pc? Did you check min configuration?
3) What is your pc specs? Hardware and software
4) Make sure you have at least 2 GB of free RAM. If you are running other softwares check using any program that shows your computer CPU and Memory.
5) Are you using the latest version of warband? 1.162+
6) Can you still load native (Warband)?
7) Any other modules/mods you have... can you load them?
8 ) Did you create a thread on support subforum and did you post your txt config files there?
https://forums.taleworlds.com/index.php/topic,336276.0.html