Elio's lowest point is basically what I talked about in certain previous asks: the <Emotionally-Stunted Phase> of his childhood - which he doesn't like being brought up in conversation and does his best to fabricate something to replace it.

It took him meeting <Mephisto the Darkrai> - who would later become his, and later - his younger siblings' foster father, and doing his best in aiding in his recovery by infiltrating the [Dreams] of New Tork's denizens, defeating their [Nightmares] - thus gaining their crystallized essence, and learning a variety of life lessons from all the dreams that he passively experienced, to have the epiphany that led to his establishment of an emotional foundation: the correct step towards the normalcy Elio had unknowingly desired for such a long time.

Regardless, his overcoming of that low point doesn't mean he won't dwell on it every now and again; he still retains a habit of convincing himself that his feelings are his own, not a by-product of meeting everyone else's expectations, and he's still human like everyone else around him.