Inductance overheating
Isat must be avoided by current limit sensing cycle by cycle to avoid thermal runaway problem. As L is rated at -10% for Imax, it continues to drop rapidly for increasing current, which in turn reduces output voltage and thus demands more current and L spirals down.
Your circuit filters out Imax peaks with a LPF so you must regulate to average current at a lower value, such that Ipk does not exceed rated current.  Increasing L tends to reduce Imax limit for same size.

Consider output power you need and what current required at 3.3V
Choose 10A choke like this http://www.coilcraft.com/xal1010.cfm