You will need to read your codes to see why the O/D light was flashing.
I'd suspect, based on your additional symptoms, that a P1744 will come up which means your torque converter is slipping. Repair would be a new TC, solenoid block, and a rebuilt valve body. That's $600 in parts and requires removal of the tranny to replace the TC.
You might get lucky and get by with the VB and solenoid assy along with a fluid flush, but by your mileage and with a slipping TC, I doubt it.
Get the codes first. OBDII scan tool. Just speculating right now.
Steve
