verse
もし今の私を見れたなら
どう思うでしょう
あなた無しで生きてる私を
According to this post accepted answer,
It's still the object marker. The sentence is just not finished and the verb is implied.
However, I don't think this is the case here. As far as I'm concerned, we can leave out を without changing its meaning:
あなた無しで生きてる私 (A)
I've done some research online, coming across the following:
を (Human emotion) marks a noun or noun phrase that serves as the cause of some inward human emotion. It pairs with inwardly-pointed verbs of emotion such as よろこぶ [To be glad]、[悲]{かな}しむ [To be sad]、[懐]{なつ}かしむ [To miss / To yearn for], and [悩]{なや}む [To be worried].
Recovered from wildnihongo
No example ending with solely を was provided, though. From this source, the construction is given by Noun / Noun Phrase + を, which happens to be the case with (A).
The source also notes that this usage of を is rather literary:
(1) を (Human emotion) is very literary and you are unlikely to hear it in spoken Japanese.
This what I've gathered so far from English sources.
あなた無しで生きてる
modifies私
to meanI, who lives without you
. Therefore, we could translate the verse asIf you were able to see who I am right now, I wonder what you would think of me, who lives without you
. This is assuming that を can be placed at the end of a sentence to indicate emotion without the need of pairing it up with a verb.