Rapidly, it is just a guess but it sounds to me like your HV contactors are not closing. Do you ever here a "clunk" come from under the car after it wakes up? If the contactors don't close, then the little LV battery doesn't have the capacity to handle much. You could try connecting a power supply (50A or bigger) to the LV system... and it will at least stay alive long enough to troubleshoot and allow time for software installs. This is my first Tesla so I am kinda learning as I go... and getting a lot of help from people on this forum.