I haven't drawn the mains side.
The current transformer has a resistor across it. Ideally you pick the value of the resistor to have about 0.5V across it at the maximum load. In your case, you can increase the value of the resistor to increase sensitivity. For the highest sensitivity you might even be able to remove it.
The diodes D3 and D4 are CRITICAL to prevent the voltage across the current transformer from exceeding about +/- 0.7V.
R2 and R2 determine the gain of the precision rectifier. It is set to 10 at the moment. You could increase that if you desire.
R5 and R6, C1 and C2, form a voltage divider to give you a split rail.
R3, R7, and R8 allow you to trim the offset of the op-amp.
In operation, you have the load completely disconnected and you adjust R8 for a 0 reading. Adjust it so the reading is just 0, going further will reduce the sensitivity. if you can't zero it, this may be due to variations in resistor values. Using 1% resistors for R3, R7, R5, and R6 will help. swapping resistors around, or carefully choosing resistors for very similar values may be necessary. In the worst case, increase the value of R8, although this will make it harder to zero the meter accurately.
Then connect your load. The meter will only read positive. If you are using a multimeter, auto-range it or reduce to a more sensitive range for lighter loads.