Yeah I learnt about sex toys by going through my parents things and finding a couple which was quite unsettling at 14 and not being quite sure what they were
Well perhaps you learned a valuable lesson in not snooping through other people's private things? That one is on you l'm afraid. This point adds nothing.
I learnt about STDs from people making jokes about them down the pub.
You should have been taught about STDs in school long before you were old enough to be 'down the pub'. I was. If your school was lacking, then I'm sorry for you, but clearly as the current SRE syllabus shows - it isn't anymore. So this point adds nothing as well.
I learnt about 'bumming' from people being homophobically abusive,
But as we have agreed that teaching about condoms will include that it is necessary to mention they are needed for anal sex - again, the current RSE syllabus should cover the fact that anal sex exists and needs to be safe. Do children really need to know anymore about it than that? I mean, is it really that complicated?
I learnt about lesbians from some dodgy video that got covertly passed round at school
Again - lgb training is in primary schools now, so this is unlikely to occur any more. Though the you tube videos may be just as 'dodgy'. But no child needs to 'watch' something that shows them what a lesbian is - an explanation of same sex attraction is sufficient and can be given to children from a very young age: 'sometimes boys love girls, sometimes boys love boys and girls love girls'. No one but lesbians need to know how it is they have sex, if we're honest, that's private business - and I don't see many lesbians advocating for videos of it being shown in classrooms.
I learnt about the difference between homo, hetero and bi, as well as what transsexual meant, from the dictionary. Anything else I gleaned from movies, agony aunt columns and when I was a bit older from just about consensual sexual experiences with older people.
This is all absolutely normal, natural and how it is supposed to be. Why do you think this is a problem?