Ed doesn't seem to realise that it is his own pain that's causing some of April's distress, but he makes an effort to reign in his own emotional pain anyway. Mostly he just doesn't want anyone to see him break down. He takes in a deep (if somewhat shaky) breath and continues.

"Al was the only family I had left. I'd gotten him killed, and it had been for nothing. But I still thought there was something I could do to save him. It was risky, and difficult, but... Like I said. Only family I've got left.

"I knocked over one of the suits of armour our dad kept in his old lab. One was a breast plate, the other full plate mail. Seven feet tall and everything. Used... the blood from my leg to draw an Alchemy array on the inside of the armor, and the same array on my right and left arms..."—he crosses his arms and touches his shoulders by way of demonstration—"and a third over my heart." He lays a hand on his chest, again by way of demonstration. "I'm not sure how I managed it, but by sacrificing my right arm, I was able to get Al's soul back and bind it to the suit of armor."