Obviously u and ur bf are serious about each other, and personally if i was ur parents i’d let u 🙂 hehe.
but at the end of the day they are ur parents, and u literally can’t get married till u have ther say so.
maybe try talking to them sensibly like sitting them down and saying how much it means to u etc etc, and definately don’t act childish about it, cos then they’ll have reason to doubt ur not ready. hopefully they’ll allow it.
but if they don’t allow it, respect their decision and just wait a little while, they are only saying it cos ther trying to protect u. and try to understand that. its not that long to wait with all uv been through together.
good luck xxx