He was completely invested in it and never saw it coming. But it was that just one moment and he was completely, in fact forcibly torn out of “something” - the thing in which his heart was completely submerged. But it wasn't his choice. He wasn't given any. Never had any in fact. It sucks but ... never hurt.

To me, there is nothing that really needs correction as such. I guess that your intention was to be a bit vague, but I think that you have overdone that. Your two it's in the first sentence presumably refer to two different things. The ambiguity does sound mysterious, but to me goes a bit far.

Your 'something' and 'the thing' are linked, so perhaps shouldn't be in separate sentences. I think you're missing something in the last sentence - it doesn't quite read right.