Nose Job - Help talking to parents?

I'd just like to start out by saying i'm 19, i've done PLENTY of research, and this is something that i've wanted since sixth grade. It's something that I truly want for myself. My nose is really my only insecurity and a huge insecurity at that. It affects my every day life, I've been teased, I personally hate it, and it honestly just makes me sad. I feel like it is not me at all. It does not fit my face or my personality. I want a nose job more than anything. With that being said I know that I should be mature enough to go to my mom and tell her how I feel and ask if I could have the surgery, but this is something that I have been trying to do for, literally, years. It's a really embaring subject for me and I've just been having so much difificulty trying to ask my mom about it. So basically what I'masking is for some advice that might calm my nerves a little when talking to my mom about it or how i should go about it. If anyone has been through asking their parents about plastic surgery I would really love to hear your stories. I'm not really looking for any negative feedback or anyone telling me that I should reconsider. I'm absolutely certain that this what I want. Thanks so much for your help =)