When there are multiple issues at the same time, it's often hard to determine if they are actually related.
If you have power to the plug that your converter plugs into, then it must not be related to the breaker that wont re-set. If the converter fan comes on for a few seconds then back off, and is letting your battery drain then it surely is suspect. To test it, you need to get a multi meter as suggested earlier, disconnect the battery cables, and with the converter on check the voltage coming to the cables. They should read around 13.5 volts. If no voltage and your certain fuses on the back of the converter are good then it most likely is the converter has failed.