Translation:I do not know how it would be if I had not met you.
Can it also mean "I do know know how I would be if I had not met you?" instead of "I do know know how it would be if I had not met you?"
Then, we'd probably say "eu não sei o que seria de MIM se eu não..." in order not to cofuse the subject "I/it"
Well, I got it wrong precisely because of that. When the secondary clause omits the subject, if there's an ambiguity I thought that the best interpretation was that it coincides with the main clause, which in this case was eu. Why would you have to assume a completely different subject? And if not "I", why assume "it" as opposed to he or she or you? Seems like you have to guess. Since the meaning of the sentence doesn't really change all that much regardless of which subject you guess, I think more of those choices should be accepted.
Just a speculation.
Maybe, if there's ambiguity, "it" is always assumed, because all other "I, he, she, você" have pronouns and the speaker would include one if he was talking about one of them.
Paulenrique, I had the same question, but have a different idea. I think what you suggest means: "I don't know what I would be if I had not met you." And what Fintan and I are asking is whether "I don't know how I would be (meaning how I would be feeling) if I hadn't met you." Since the conjugation of the conditional is the same for I, he/she, or it there is no help there.
You are correct that it is very ambiguous. However, in reality, if you were having this conversation with someone, there would be context - which is lacking here.