About misunderstanding of Lenz law
The induced voltage always try to oppose the change in current. 
So, your polarity is wrong.
The inductor at the beginning has no current. And the current source wants to increase the current in the inductor. So the induced EMF must oppose this change (stop the current to flow).    

The voltage across an ideal inductor is \$ V_L = L*\frac{dI}{dt}\$

This equation indicates that inductance voltage depends not on the current which actually flows through the inductance, but on its rate of change. This means that to produce the voltage across an inductance, the applied current must change. If the current is kept constant, no voltage will be induced, no matter how large the current. Conversely, if it is found that the voltage across an inductance is zero this means that the current must be constant but not necessary zero.



In summary:

When the current is increasing di/dt > 0, so V must be positive because L times a positive number yields a positive voltage.

When the current is decreasing di/dt &lt; 0, so V must be negative because L times a negative number yields a negative voltage.

When we have no change in current over time then we cannot have any induce voltage V = L*di/dt = L * 0 = 0.

In the circuit below V2, V4, V6 source represent the "induced" voltage. 
As you can see only "positive voltage" oppose the current.







simulate this circuit &ndash; Schematic created using CircuitLab