This is why you must analyse, must understand how it was done. Don’t slap it away, don’t try to ‘live past it’, confront it, and see the tricks. See how the Abuser got inside your head. How s/he was able to ‘rewrite’ reality to the extent that you believe what you ‘know’ is not true.
You need to see the tricks so that it never happens to you again, and that you can protect others from it happening to them.
Once you can sit back and see exactly how he got into your head you can see how another Abuser is doing it to someone else.
Sometimes, simply having a witness, or recording statements are enough. This prevents him from “I never said that,” “You never told me that…” when there is a breathing witness or a recording of exactly what was said.
Gaslighting is real. It happens all the time. When you are aware of it, it fails.
Abusers are masters of gaslighting.