First of all you must know you didn't do anything wrong.
Prophet Muhammad peace be upon him, said:
“O Ali, do not follow the gaze for the first, and you do not have the
second one.” Narrated by al-Tirmidhi 2701 and it is in “Sahih
He said in al-Tuhfa: “His saying: (Do not follow the gaze with the gaze) is from following, that is, do not follow it, and do not make another after the first. ".
Thus it becomes clear to you that deliberately looking at a non-mahram woman, as well as continuing to look after a sudden look, is forbidden.
We ask God to protect us and you from all other taboos, and God is the Guide to the straight path.
So about the waswasah there are things that should help you in that
- Keep reading the Holy Quran.
- Preserving the morning and evening remembrances (adhkars), and the remembrances (adhkars) of sleeping and waking up from it.
- seeking refuge in Allah- from the accursed Satan and his temptations.
- beneficial actions that bring the you closer to allah.
I hope my answer can be useful in one way or another.