Black smoke comming from tail pipe on 2004 ford f250

What is your question?

Loss power would not move go dead in drive put in neutral idle fine step on gas pedal black smoke started comming from tail pipe killed truck crank back up and has been running ever since but still is blowing black smoke out of tail pipe when idle and when u press gas more smoke pours out of pipe what could this be put a can of sea foam in tank after this started thinking bad fuel maybe