Check out my blog post on this topic.

I had the best luck with SSIS (Attempt 4):

https://thesqldev.wordpress.com/2014/07/02/importing-data-in-a-mysql-database-into-a-sql-server-database/

For your case, if you have to stay in T-SQL, see attempt 3. Items 7-10 detail the issue you are facing and how to work around it.