You're allowed to upload it here. Mature content is allowed UNLESS you put mature filter on- what I mean by this rule is, before uploading, make sure you tick the box that says "contain mature content" so that it shows as a warning page to other people. Mature filter makes your mature content unavailable to people under 18:
help.deviantart.com/220/This rule applies to pornography, violent artworks...etc
But your submission is a journal, so I don't think it matters- you can just upload it