An adjective that describe special kind of loneliness and foreignness/strangeness

'Alien' and 'Outcast' don't do all the work you require, so perhaps a compound, a poetic device, like "Stranger in a strange land" - which has religious (Exodus) and literary (Heinlein novel) associations. Or "Square peg in a round hole." "Sticking out like a sore thumb." "Like a dog with no tail." Many more, I'm sure.

removed adj. OED

distant, remote, or separate in space, time, or relationship

As in: Children of the Resolution By Gary William Murning

I felt removed from everything about me. But that was the way I wanted it, I told myself. I was not a part of it, it was not a part of me.