2007 Cadillac CTS jerking

Lately, my car has been jerking but it only does it if I am in stop and go traffic. If I can accelerate without any cars in front of me, it’s smooth as ever but if I press the gas then have to suddenly let off of it because the car in front of me is going slow, I feel it jolt, usually at about 40 MPH. Once I can get to a constant speed, it’s fine but its a problem when I have to keep varying my speed. It never did this before that I can recall. It hasn’t stalled but it feels like it could.

Have someone try cleaning the electronic throttle body.