Guido,
This doesn't make much sense to me at all. In fact, it seems that you're adding premises here that you explicitly denied in your OP.
A1. Nothing belongs to the consciousness because it is nothing but the self and free will.
A2. The unconscious mind does not belong to the conscious mind.
A3. The personality belongs to the unconscious mind.
I don't even know what any of these three premises mean.
B1. The world is sustained outside of the contents of the conscious mind.
B2. Thus the world exists within the unconscious mind.
I would challenge you to think more deeply about your views on the conscious and unconscious mind.
Based on A and B we can conclude C.
C1. The world does not exist within one’s own mind.
Huh? Isn't premise B2 that the world exists within your unconscious mind?
D. We observe people that have the same conscious nature as ourselves.
Didn't you say in your OP that we CANNOT observe this? We cannot observe other people's consciousness.
Maybe you meant to equate observable behavior to "conscious nature"?
Instead of trying to answer those questions, I'd strongly encourage you to read "The Embodied Mind" by Valera, Thompson, and Rosch. I think "
embodied mind" is the best approach to understanding your questions and doubts and ultimately answering them by denying the premises which underly the question.
Specifically, if you start reading on p.23, where they begin talking about mindfulness/awareness with respect to practicing Buddhism, you may find something useful.
I think the book should be pretty accessible (both physically and mentally
) to/for you.