Relationship uncertainty need help

I need help with Jealousy/uncertainty in Relationship. We had a Situation yesterday We were driving in the car when a woman was walking on the left side of the road. I had the impression that my partner looked at her, and I felt uncomfortable. Shortly after, I brought it up to him. I’m not completely sure anymore, but I think he asked which woman I was even referring to. but i’m really not sure anymore that he ask this.. it makes me upset Because if he actually asked that, then it doesn’t really add up that in the next moment he suddenly knew which woman I meant. But like I said, I don’t even remember clearly right now whether he said that at all. He said he did not look at her, only noticed her. He said he was looking forward, then at me, and only then became aware of her. However, I remember that he did not look at me at that moment because I was looking at him, and I am quite sure he looked at the woman for a few seconds while we were approaching her. When I told him that his explanation didn’t make sense to me because he had not looked at me at that moment, he became angry and said that we shouldn’t be arguing about this at all and that he was upset that I did not believe him. This kind of situation has happened several times before. Either he is lying to me or he has a distorted perception that he interprets in a way that fits him I’m not sure. The fact is that we cannot come to an agreement in situations like this. He does not want to admit that he looked at other women, while I also feel uncomfortable with him doing so. Since we cannot find common ground, and he insists that he did not look, I feel quite desperate. My therapist said that there is nothing I can do except change how I handle the uncertainty. So I am currently trying to tolerate the fact that I may never know whether he is lying, misremembering, or interpreting the situation in a biased way. I cannot accuse him of lying, because that would only lead to conflict, and I do not want to accuse my partner even though I sometimes feel that he might not be telling the truth. I also struggle with similar situations, for example on social media. An influencer we had talked about before (her husband is a celebrity my partner is a fan of, and she is also known as an influencer) suddenly appeared as a suggestion on his account when I was on his phone. He generally becomes defensive and annoyed in these situations because he says he does not look at or search for other women. The same happened in the past when, before our relationship, he had followed and liked a specific influencer for years and had even added her on Snapchat. This influencer suddenly appeared on my TikTok “For You” page during our relationship, which felt very noticeable to me because I generally get many recommendations related to his interests. However, he reacts very sensitively to these topics, so it is difficult to talk about them. He feels hurt by my mistrust and becomes defensive. In conclusion, I struggle with how to deal with these noticeable coincidences and the uncertainty they create. I generally don’t see my partner as a liar, but I do have the suspicion that he might sometimes, possibly even unconsciously, interpret or frame certain things in a way that suits him better. However, this is only a feeling. And again I end up at the point where I cannot know this with 100% certainty. I have started ACT therapy, as my therapist suggested, and I began trying to tolerate uncertainty since yesterday. Since then, I feel completely emotionally empty and numb because I am no longer seeking reassurance. Is this normal? I feel really unwell.