No, I a tutor isn't necessary, neither is a teacher. All you really need are some books or just use the internet. Language difficulty has nothing to do with it. Chinese is only categorized as "difficult" because of the writing, the grammar, sentence structure, etc, are easier than English.
Honestly, the internet or some books can be a better tutor than any, well, tutor.
Taught myself Japanese and I'm teaching myself French.