IMHO:

I always viewed the word sex and the word gender to be one in the same, 100% interchangeable. All of a sudden (within the past 10 years) they aren't the same.

They're redefining the meaning of words. This is straight out of Orwell's 1984 (newspeak). He who controls the language controls culture. Granted language evolves over time (bad means good, sick means cool) but that change is organic and slow. The evolution of the meaning of sex/gender was not natural; it was immediate and deliberate. Our enemy has infiltrated our institutions and is deliberately poisoning our minds with ideas meant to divide us. I would assess that our enemy's tactic is highly effective in causing division.