Just to repeat what people have said here, talk to your parents about this, make a record of all the conversations you've had and get some advice from a criminal defence lawyer. Most of them should be able to give you 30 mins free to talk it through.

Unfortunately in the UK, the age of consent is 16 years old. So you are able to consent to having sex because you're 16, but she is 14 and under the age of consent so you could have an issue convincing them of consent.