You can compare your length of text with the source text.
If len(Text.text) <source_X -> Append text tokenat(source_X, len(Text.text), "")
ELSE
set text = ""
Add 1 to X(X will be ID of your source in an array)
Set source_X to Array.At(X)
The Array will contain all your text, when you finish the current text, you can move to the next ones.