Possible tooth rot after wisdom teeth removal

About three weeks ago I had my two lower wisdom teeth removed. I’ve kept with my surgeon’s instructions, I’ve watched what I ate and I brushed every day and I took my antibiotics. The week after the removal during the follow-up appointment, he said everything looked good and gave me a curved syringe like tool for applying mouthwash to the two open areas where the teeth were removed, which I’ve done almost every day.

Lately I’ve been concerned about one of the teeth next to the extraction site developing tooth rot. It isn’t visible from the top of the tooth, and I haven’t found any visible signs, but I have much more sensitivity to hot or cold food back in that small area, and I feel like the area is creating a bad smell/taste.

Is this tooth rot? Or is this normal?