"Ἀλλὰ τοῦτο ἔγωγε,"

I met a sentence from Xenophon (maybe adapted):

Ἐπεὶ Σωκράτης τοῖς φίλοις διελέγετο, παρὼν δέ τις Ἀπολλόδωρος θαυμάζων ἰσχυρῶς αὐτόν· “Ἀλλὰ τοῦτο ἔγωγε,” ἔφη, “ὦ Σώκρατες, χαλεπώτατα φέρω, ὅτι ὁρῶ σε ἀδίκως ἀποθνῄσκοντα.”

I’m not sure about the “τοῦτο”. Maybe it is used to emphasize, means “It is me that…”?

τούτο—neuter!—is just the direct object of φέρω, lit. “I bear this most difficultly.” It anticipates the upcoming ὅτι clause. We could translate: “This is what I find hardest to bear—seeing you put to death unjustly.”