If the source of the problem primarily is the 60 MB file, you could consider purging the biggest models, e.g. by:

1) Save and compress your file
2) Make a copy
3) Rename the copy to .zip
4) Open the .zip and search for all files
5) Sort the search results by size

Then go back to the original and remove the items that are disproportionately big first (make yet another copy) - and possibly find alternative models for the big ones. ok