2011 Chevrolet Tahoe stability control problems

Was driving highway when suddlenly the engine power was reduced and traction contriol stability track cam on and said to service was going 65 dropped to 45 almost got hit by rig.was near exit pulled off but car accelerated through light even though foot was on brake, took corner very fast and back into a gas station where I whipped it into park and shut off engine.turned engine back on after I calmed down check engine light was on, after idling forabout 15 min the same thing happened the engined reved then powered…

I was driving on the highway at approx 60 MPH. The truck dropped speed rapidly and without warning. Lights starting flashing and stating reduced engine power - service stabilitrak. When attempting to pull over I applied the brakes and the truck lunged forward. This happened three times before the engine sputtered and shut off - on the highway. Gm/chevrolet states this is not under warranty. The truck is less than 3 years old.