You need a mason that other mason's hire when they have a problem. He
would probably recommend digging out the back of the wall, putting in
drainage tile and fabric properly (so gravel is separate from dirt and
neither goes thru weepholes). He might also be able to reinforce the
current wall after pushing it back in position. Call a few large
masonry companies and ask who they use to solve their problems. If
you live in Raleigh, NC I could tell you the right guy to look at it.