Glad you're up and around a bit.
I've learned a little about gallstones after a friend of mine was suffering from them. I don't think "fat" is the main issue here - sounded like it was more to do with oxalic acid in foods.
Here are a couple of articles from Mark's Daily Apple.
(Of particular note was the fact that vegan diets might actually increase the chance of stones!)
http://forum.marksdailyapple.com/forum/the-primal-blueprint-forum-discussion/primal-resources/15209-definitive-guide-to-gallstoes-gallbladder-problems
https://www.marksdailyapple.com/high-fat-diet-gall-stones-and-nafld/
Anyway, I would strongly suggest checking out the alternative communities to see what their advice is.
Regardless of your chosen path, I wish you all the health you can have!