sounds like fan motor running extremely loud, check engine light on, steering assist warning light on, car shuddering when accelerating
If engine compartment fan seems to be running more than normal, you could have a cooling system problem. Suggest to take it to shop for eval immediately, check coolant level, and watch coolant temp on dash board at all time. Any signs of overheating, turn off engine and have your GMC towed to shop. Very expensive damage can occur if engine overheats even for a short time.
Beyond that, ask shop to read the diagnostic codes stored in computer memory. If check engine light is on, there will almost always be diagnostic code(s). Post them here for more ideas.