He didn't follow you and ask you to stop. I'd let it drop. You were at fault. It's called an unsafe lane change. Take several deep breaths and be thankful that you did avert an accident. And that he didn't want to exchange information. Much less complicated this way.
No you don't have to report this to your insurance company nor do you have to have it repaired. Chalk it up to the first of many scratches your SUV will get over the years.
If you didn't change lanes, then it's probably not your fault.
You take your vehicle to a garage for an estimate when you want it repaired. You report it to your insurance company if you want them to pay for the repairs. Keep in mind that your insurance rate goes up after so many reports that require repairs. I would not repair or report a minor scratch. You'd be surprised how much they cost to have repaired.
Later: even if he does report this to his insurance company all that will happen is your insurance company will contact you. They will handle it from there. I didn't call my insurance company when I rear ended a car that stopped suddenly. Accident was my fault. He said he wasn't going to report it, so I didn't. Then he did report it. My insurance agent called me. I told him the story and they took care of it from there.
I would not worry about what if's. Relax! Even if he reports it you're not in trouble! BTW, I'm a retired police officer.