Trans not working after you let it sit

[magnumv8]

I've got and 07 f350 and my trans works fine when i crank it up and drive it but if i stop somewhere to get something quick at the grocery store wether i shut it off or left it running and go to leave it starts bucking and the trans temp gauge will read nothing sometimes... if i go to stop at a red light i can feel it kick in and out and eventually driving it for a couple miles it will go back to normal, I also noticed if im reversing i can see my reverse lights kick on and off simultaneously with it going in and out and can hear my reverse relay and a solenoid in the tranny kicking in out. Today when the truck was completley cold i turn the key on to the on position but truck off put the truck in reverse and walked away when i came back i could hear the relay kicking on and off with the truck off the entire time. and i noticed my o/d light will kick off if i go to set it along with my cruise crontrol

[turbotibbo]

is the tow haul light flashing ?

[magnumv8]

no only if i go to turn it on then when ever it starts jolting itll kick off simultaneously with it and will stay off untill i press it again same with the crusie control