No expert, but maybe look into foundation patch, for where I am, it's a rubberized sheet that would glue to the outside around the affected area. Once back filled, the pressure from the dirt is more than enough to keep it in place. I have done that kind of repair before, and it worked for years after till the place was sold. As repairs go, it's inexpensive. You just need a shovel time and the patch. Just do your homework as to it being a viable solution for a block foundation as mine was poured, but I don't see why it wouldn't work. As was said before, trying to fix it from the inside is an uphill battle.