Transmission oil pressure sensor broke - code P703

2006 Dodge Ram 2500 Power wagon with 57,000 miles on it – I was off road hunting, when I got back to hard road the check engine light came on, It drove fine through 1st ,2nd, 3rd gear, when it hit drive it totally slipped, I pulled over and looked under it, no leaks or anything obviously wrong, started again, same fine up to drive and it slips as it goes into drive. I drove it 2 miles home in 3rd gear without any slipping. Once in my garage my error code reader gave me a P703 error, Google pointed me to the transmission sensor and I discovered the “Transmission oil Pressure sensor” had broken in half. Guessing a stick or rock caught the wire. So I removed both halves of it and went to Autozone to buy a new one. After installing the new one the truck would go forward and backward in my garage without problem but the check engine light was still on, so before trying to drive it I used my code reader to clear the error code. Now the truck will not move in any gear, Nothing at all, dropping in gear does not put load on engine or seem to engage the transmission at all. I checked the fluid not running vs. running and it does drop about 1/8 of an inch. I reset the ECM by pulling the correct fuse and turning on the key until it beeps 2 times, replacing the fuse and hoping a reset of the ECM would clear the issue. Nothing. I unhooked the battery cable overnight again hoping to reset the error condition, no help. Why would resetting the error code change the transmission problem? Is something else still need to be cleared? Hard for me to believe the transmission clutches are ruined when reverse / 1st worked one minute but not right after clearing the code. I understand the limp home mode should have been allowed me to drive it at a low speed. I understand drop in fluid pressure is why bands fail, but this doesn’t make sense. I have no error codes at this time.