Don't be hard on yourself. It is possible the interviewer had a bias towards you.
Here are some interview biases you might want to be aware of.
This is when the interviewer forms an opinion of you based on your religion, race, appearance, gender, or any other type of characteristics.
It is advisable to minimize or avoid talks related to any of your characteristics that are not clearly visible.
This is when the interviewer senses a small amount of negative info from you. Thereby, using it to base the hiring decision off from the info.
Truth is, humans are naturally and subconsciously attracted to positivity. Hence, show a more positive side.
This is when your interviewer makes a decision off your first impression (either bad or good) as the first impression eclipse's your performance through out the interview.
As always, in everything, always give a great first impression.
This can either be in your favour or not.
Halo is when interviewer lets one positive fact about you override everything else you say /do. The Horn Effect is the opposite & allows a weak fact to influence everything else.
Just hope for the best in this case.
This is when the interviewer is able to distinguish between your socially acceptable answer rather than revealing your true opinion about a question.
It is always advisable to be professional and not allow your ideologies play in your interviews.
This is when the interviewer compares you to a stronger candidate who might have been interviewed before you. Hence, the comparison comes in play affecting the decision on yours.
In this case, just always put in your best and be optimistic.
This, in many cases, always works in your favour. This is when the interviewer sees a similar trait in you that they have. Hence, it affects the decision they make on the interview.
You can always research your interviewer in order to influence this.
That's why organizations have to continuously orient hiring managers / recruiters and even HR of these biases.