99 7.3 automatic- truck shuts off when shifting to reverse

[powerstroker.seven.three]

I have a 99 f250 superduty with a 7.3 and an automatic. a few weeks ago while parking i shifted from drive to reverse to back up and when the trans engeged the truck shut off. put it in neutral and it started right back up and shifted into gear and was fine. then yesterday i started the truck when it was still warm and went from park to reverse and it shut off. went back to park and it started right up. went to reverse again and it almost stalled the engine but didnt. then i just kept going from reverse to park and bck to see what was happening and 5 more times it almost stalled the truck but didnt. my friend said he thinks its thetorque converter. anyone have any input? the truck also shakes occasionally when going downhill not touching either of the pedals. it also shakes very slightly at idle