The issue is probably that your webhost doesn’t allow more than 2mb or so of data to be imported at once. You can resolve it one of two ways:
https://www.blink7.com/2009/05/14/importing-and-exporting-large-wordpress-blogs/
1) You can change your webhost settings to allow larger files to be posted
2) You can split up your file into smaller files.
https://www.gbmini.net/wp/2008/11/splitting_wordpress_export_import_file/
Hope that helps! ??
