I should mention, when I have said Currents Equal and Opposite, be carefull of the Turns and the Timing of the Circuit.
Often what appears on the scope, may be completely different from what you may expect! As an example:
The above image has a 31% On time, seen partly on the Red Trace Zero Graticle Line, all the rest is off time. None of the Currents are inverted!
Take special note of the very large Negative Current on the Yellow Trace! It almost appears as if the Current on the Yellow Trace is moving backward in Time ( t ).
These currents were only supplied from a 400 ma supply, the total on the scope is: 1152.7 Amperes.
So take your time and study carefully!