Since noone yet has answered to this very courageous posting I feel the need to say something.
Well, I think after your description of your feelings when in diapers I for the first time understand something about this. The feeling of being safe, of merging with inner child. Obviously it is something way more than just sexual fulfillment.
To me this sounds pretty much like my own need for bondage, wich nowadays is a bit more accepted as a very common fetish. When in bondage I, too, have feelings that have nothing to do with sexual fullfillment. I feel safe and held, in touch with a part of myself that is usually repressed. I feel that I can relax. I also feel that I would want to be in bondage a lot more often and that I would want others to know this side of me. Though I choose not to be public about this not to make others uncomfortable or myself vulnerable to predudice.
What I want to say is that I don't think your diaper obsession is weirder than any other need to go back to previous times in life and bond with inner children or reenact something or whatever. The diaper thing is no more strange to me than the need for bondage or violence or whatever else anyone might need to deal with.
Though I would strongly discourage any permanent changes in your bodily functions. You never know how you will change as a person in the future and constant need for diapers could be a huge problem. Just like I know it would not be good for me to engage in a real dangerous relationship even though I have a strong desire to do so. Fantasy and reenactment when you choose to is very different from not having a choise. But that's just my opinion.