Short circuit problem (batteries getting HOT) within circuit
Without knowing the pinout of your DPDT switch it's difficult to say for sure, but from the image it appears you are indeed shorting out your battery through the switch. I also don't see how the microswitch is working. Can you try to redraw your circuit using standard schematic symbols? It will be much easier to see and understand the functionality of your current setup.

A standard motor reversal configuration using a DPDT switch is shown below:



Please provide some clarification of what you are trying to do with your microswitch. As described, it does not make much sense. If you intend for the motor to only run in reverse if the DPDT switch is set to "reverse" AND the microswitch is closed, then you can put the microswitch between the opposite corner terminals of the switch in the above graphic (replace one of the diagonal wires with the switch). 

EDIT: Updated recommended circuit diagram:



Note that both micro switches are configured to be NC (normally closed).