Xbox has a "Reserved space" for mods. If the crashes are being caused by a mod, you can try removing everything in there. You will have to reinstall your mods but the game should at least start again.
It should be in the settings of your Xbox, not the game itself. I don't have an Xbox so I'm not sure where exactly to find it, but it should look like the screen in this post. The 2GB is the space for mods.
