Help with understanding what’s going on? Maybe transmission

The last couple of days when I’m driving my truck it will just start slowing down and jumping and then “shift to park” will come up on the screen. It seems like a transmission issue but has only recently started giving me issues these last two days. When I had to break hard, it seemed like the engine just shut off? And when we went on to drive after that it wouldn’t go even with my pedal all the way pushed then it jumped and continued to go slow. It just went off and won’t keep the engine on after multiple attempts. Any ideas as to what is going on?