skunktastic : I agree with you that it was a mistake to bring it up in the heat of the moment. This is the sort of thing that should be brought up when there are no distractions, as a conversation and not a reaction. When you bring it up as a reaction, it’s easy for someone to become defensive and everything derails.
I disagree with pretty much everything else though. This is not a situation where you are dressing up nicely for work and your husband accuses you of cheating out of the blue. This is months of you not acting as you normally would and your husband noticing these changes in you. The OP is upset because of a sequence of events for 8 months, not because a couple things happened in the past week or so. In the first case, you are absolutely right that it’s premature to bring something up, but I don’t think it applies so well to this particular situation.
I know you have the best intentions, but I’m not sure what your advice was here. It seems like it was just ‘don’t bring up difficult conversations because he might get mad”, and I’m not sure how that is helpful. And as useful as it can be to speak to a therapist, not every couple needs to run to a therapist every time they need to have a difficult conversation. But I might be misunderstanding your advice here.
OP, I know it didn’t go as you wanted it to, and I’m sorry. Which is why I really want to stress that when you have conversations such as these, it isn’t something that you just put off and put off and put off until you absolutely have to have it. By doing so, you become more stressed and upset, and then discussing it becomes a reaction that puts him on the defense and you as the attacker. What you want to do is have a calm conversation stating your reasons and asking for clarification. The fact that he flew off the handle could mean two things. One, there is something going on and he became extremely defensive and gaslit you, or two, there is nothing going on but he felt attacked and freaked out at you.
Either way, I think that the best thing you can do at this point is go back to the original advice I offered. Sit him down, tell him something like, “The conversation we had about Amanda the other day was really upsetting, and I’m sorry that it happened the way it did. It wasn’t the best time to bring up my concerns, and I know that it made you feel attacked and hurt. However, I think it is really important that we talk about what happened here leading up to our discussion, so that we can best figure out how to move forward from here. When you started your job 8 months ago, I started noticing xyz. This seemed really different from how you normally are. I don’t want you to feel like I mistrust you, and I’m not accusing you of cheating on me, but it has seemed to me for awhile that you might have deeper feelings for Amanda than strictly professional. If that’s the case, I don’t think you are a bad person or that you are trying to cheat on me – just because we are married does not mean that we won’t be attracted to other people, and I understand that. However, if this is the case we need to discuss that and see how to move forward. If it isn’t the case, then we should also talk about what led to the idea and what we can do in the future so that we can become stronger as a couple. My intention here isn’t to shame or accuse you, but to work with you as a partnership so that we can understand each other better.” And then listen to what he says.