First off, wanting to wear diapers is far from being rare and is not a bad thing at all. It seems like you're the only one in the world who wants to wear diapers only because it isn't something people talk about in public. I share the same desire.
You are what is called a TB/DL. TB stands for Teen Baby, DL stands for Diaper Lover. A Teen Baby is a teen who wants or enjoys diapers and any number of other baby stuff, which could be pacifiers, baby bottles, high chairs, baby clothes, etcetera in any combination. A Diaper Lover is someone who enjoys the feeling they get from wearing a diaper. For them, it's less of a "baby" thing and more of a "sexual" thing. Someone could be a mix of both of these: they could want to be a "baby" at times and at other times might only want to wear a diaper for the feeling is gives them.
Now I hope I haven't confused you with all that. Now, there are a few things you need to do:
First, figure out what it is that you like about diapers. Do you like the way they warm you up, hug your waist? Do they make you feel relaxed because you know that if you have to go, you won't have to try as hard to keep from wetting yourself? Or do diapers remind you of how a baby doesn't have a ton of worries, and the idea of wearing them make you feel worry-free? You can research more on the internet, but don't for one second believe the sites that say that wearing diapers is a bad thing -- words that might be used include "disease," "mental problem," "perversion," and other things. Diapers won't kill you, but drugs and alcohol, which seem "normal," are a danger to the addict and anyone around them.
Second, talk to your dad. Before you do, think about what you might say, and be sure you can answer what questions he might ask. If he asks a question and you don't know the answer, admit it, don't make stuff up. When you talk to him, do it when he isn't stressed, and have both of you sit down and talk. If there's a TV turned on, turn it off. The hardest part will be going up to him and telling him you need to talk to him. Once you get started, though, it'll be a little easier.
You might say something like this:
"Dad, I know this may be hard to hear, but I'm a... (teen baby, diaper lover, say what you are, or say "I like diapers") Before you start asking questions, listen to me. You're asking yourself what you did wrong raising me, if this is a joke, and a lot of other things. You weren't a bad parent, and this isn't a joke. It's not just a phase that will go away after a while, either. I just like diapers..."
Some more things you will want to say would be:
Wearing diapers is much better than doing drugs or having getting a girl pregnant.
Nothing will make you "stop" wanting to wear diapers, and there's not even an honest reason to try to get rid of it anyway.
If he freaks out or rejects you for liking diapers, you will be more likely to lie to him about other things, to get diapers without him knowing, and less likely to talk to him about more serious things, such as if you start using drugs or other things. You will also go down a path that ends with you being mad at yourself and your desire, and could even bring you to suicide.
I'll stop there.
Hope I helped.
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