Just to address the title of your thread: being invalidated constantly by those closest to you is incredibly crazy-making. Simply maddening. It creates a situation where you totally fight to be heard and acknowledged, to no avail. And as the invalidation continues, so does the gaslighting and denials. You hold on for dear life to reality, your truth, but it is a no win as long as you are around these people.
What you feel and experience is real. They are the ones with the problem. This type of emotional abuse is one of the worst kinds because it creates a situation where you are constantly battling for acceptance. Banging your head against the wall over and over hoping for a different result.
I hope you will stay here, keep posting, regain your self esteem and believe in yourself. It is not you.