I saw the OW

Lil and I were in the supermarket the otehr day, we needed to pick up a few things for dinner. We were walking up the isle past the energy drinks when I spotted a woman who looked like OW. I did not see her entire face but I saw enough of her to make me think that it was very likely to be her, a 90% possitive ID. The hair, the jaw line, the way she walked, her general appearance, they all fitted. I did not tell Lil that I had seen her, I just kept us moving away from OW, down to the end of the next isle and then we had to go back up the next isle. I hoped that OW would be gone from that part of the store by the time we got back there, but she was still at the end of the same isle. As we came out of the isle OW very swiftly went down the isle and away from us, it appeared as if she was keeping her face away from us to avoid being seen. I did not see her again. After the first sighting of her I asked Lil if there was anything else that we needed, "cat food" was the answer, so we headed back for the cat food, then she wanted to get beer. The beer is at the other end of the shop and I did not want to go down there for fear of seeing OW again, so I said we could get the beer from another shop, I made it clear to Lil that I wanted to get out of the shop without telling her why.
She got the message and we left swiftly. Once we were in the car I told Lil that I had spotted OW in the shop, Lil was a little bit pissed that I had not told her in the shop.
How did seeing her make me feel? The first thought in my head was "is that really her?" I even looked back to try and see if it was, at that point I felt the FOG coming over me and I knew it was time to get the hell out of there, I felt repulsed by the thought of being near OW and I wanted to protect Lil from an encounter with her.
I have not been to town with out Lil since then. I keep my eyes open for OW when we are in town now, just in case she is back in the area and so that I can stay away from her if she is in town at the same time as us. I know it would be too easy for me to break NC, I also know that it is not worth the damage.
I wish I could just erase her from my mind.

So did I do the right thing by not telling Lil I had seen OW while we were still in the shop, or was it OK that I waited until we were outside? I guess I should have told her straight away, but I was starting to feel insecure, like an anxiety attack was going to get a grip on me. I had so many anxiety attacks when I was having the A, it was bloody horrible, I don't want to have any more of them.