I'm wondering if anyone can lend me some guidance to get this circuit functional. I'm trying to hobble together an output filter for a DC-DC converter with jellybean parts. The noise is roughly in the 500kHz/200mVpp range. So far I've managed to get rid of the noise with an LCL filter (pictured below), only when I connect the output to the load the voltage drops from 5V to 2V.

Can anyone explain how I can remedy this situation? Is the voltage drop happening simply because there's too much current flowing through the inductors? The load itself is somewhat power hungry: three Red Patayas that draw about 3A in total, as well as some smaller filters that draw about 100mA altogether. Unfortunately, I'm uncertain how to calculate the impedance of the load itself... when I stick a multimeter on it it reads 300 ohms, although I realize it's not that simple.

Anyways, any pointers would be greatly appreciated.