You have to let it happen. There will probably be a lot of suffering but rising labor costs will force solutions like automation. Most social issues in developed countries, like people having less and less relationships, are due to urbanization and technology which is more difficult to solve, but immigration is not going to fix that anyway. People recognize that endless growth is not sustainable but are too terrified of the alternative, as soon as it shows signs of slowing they want to keep it going by any means necessary.