2007 Jeep Patriot no power

Going 70 on interstate.
Lights on dash flash on, then turn off
Car suddenly decelerates
Pull off to side of the road, turn off car.
Turn it back on, drives normally with check engine light on.
Drive to school next day.
Come back out, try to start it up.
Nothing at all.
Switch out battery.
Slow to start, but starts and drives home.
Won’t start; no electrical power whatsoever.
When key is in on-start postitions, slight ticking/thumping is heard but only in the cab.
No dash lights come on when key is in on-start positions.
A day later, fuel gauge comes on and is at about 1/3 tank, flickering up and down without key in ignition.
Will not shift out of park with key in the ignition turned to on, with foot on brake.
Have tried taking off battery terminals and reinstalling multiple times.
Nothing happens at all, but there are sparks when battery is reconnected to leads.
Key fob controls do nothing.
Must manually unlock car door with key.