I’m very sorry to learn that the UK adopted the USA-style approach to sexual education. My own experience, a couple of decades before yours, was totally different and the parents of those I knew in the UK were far more relaxed and open about sexual matters than your parents appear to have been. Perhaps I was lucky enough to catch the end of the 60s & 70s period of sexual liberation, whereas you unfortunately caught the consequences of the UK importing so much US pop culture and along with it all the dire sexual repression that’s the US norm.