Mesh Analysis for Complicated Circuit
I guess you see a current loop which goes through your both current sources and the 4kOhm resistor. You got stuck because you couldn't figure out how to write KVL equation for that loop.
But that loop doesn't need an equation, it has current 0.001Vx/8
You need 2 KVL equations which contain unknown loop currents of the voltage sources.
The third equation is got by setting the sum of loop current from voltage source Vx/2 and loop current 0.001Vx/8 equal with minus 1uA. This trick (=to present a current source as a sum of 2 loop currents) is also used in many supermesh examples although this isn't one of them.