Not sure if you'll be happy with it, but 'self-delusion' comes to mind, tagvail. There are many ways of conveying the phrase you're talking about, but those too are phrases.
Your use of 'hype' in this case not only seems to imply excessive or exaggerated publicity, but misleading information or even outright deception (of oneself) through publicity.
The film 'The Great White Hype' has an excellent example of this, btw. S.L. Jackson says something like
'You're starting to believe your own bullshit!'
Will that do?