Migrate paragraph fields
I would approach this differently. Using PHPMyAdmin or a Database viewer program, I would look at the Database for the paragraph fields table. Then just export table from D7 as a CSV file. 

In D8, fill out 1 node paragraph values, just so you get the table structure, and export table as CSV.

Then with excel (or Libre office Calc) copy and paste values from one CSV to another. 

Import CSV to D8 Database. 

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