[SMALK THE FORGOTTEN CITY SPOILERS] Why does the game keep crashing? (Skyrim SE, Xbox One)

I've put a good few hours into this qest, and haven't had any problems with it. I then got to the point where Dooley gives you the key for his treasure and you proceed to try and find it. I pretty much knew straight away to look inside the sunken house, and then follow through the trap door to the cave.

Once I got to fighting and defeating the Cave Dwellers, I then saved it. It crashed. I reloaded it, then had to go through the cave a second time, and it happened again. However, this time, instead of saving I just went into the lonely tower, then it crashed while loading it.

This time, I tried just sneaking past them and going into the lonely tower by lockpicking it. Crashed again. I've tried every conceivable way to get on with the quest, but it always seems to crash, whether its by saving the game or loading another area. I'm really not sure what to do.

Any help would be very appreciated, thanks.

*SMALL, not SMALK