I was in a minor car accident...I’m still freaking out

I know this is completely unrelated to pretty much anything on this app but I’m freaking out. I have really bad anxiety and I’m worried as hell. So I was at a stop sign waiting to make a left hand turn. I see they everything is clear and then continue to make the turn. All of a sudden I noticed a car coming toward me in the right lane and the BACK of my car and the FRONT of their car skimmed. The only damage that was done was scratches on both vehicles, but I gave them my insurance information and swapped numbers.

Here is the thing: I swear on my life I did not see a car in that lane, but I question myself on the smallest things (hello, anxiety).

But if I truly didn’t have enough time to make the turn, they would not have hit the back of my car, right? They would have either hit the middle or front of my car. If they were far away enough to just hit the back of my car they had to be speeding or they either sped up trying to not let me out.

Am I wrong or what

Also what is the worst thing that could happen IF it was my fault