Newcastle won the tie on penalties after the score finished 3-3 at the end of extra-time.
Iraola told the Daily Echo: “It's difficult to find a more FA Cup game than this one, I think, very difficult.
“Alternatives from both teams. We've been losing. We've been winning. We've been very close to winning it. We concede the 2-2 in the stoppage time.
“I think we played also well the extra time. Probably we missed two situations one against one against the keeper from Alex Jimenez, Alex Scott. Probably we should have done better.
“We found a way to score the 3-3 at the end. Then we go to the penalty shootout, we've been the ones out.
“I think even the penalties, 18 penalties. I’m proud of being part of this game. But the truth is you want to go to the next round and this is what matters in the cup and we are unfortunately out of the competition.”
He continued: “I think we've given everything, both teams.
“I think we've had also during the week very difficult games. We played Spurs, we won at the last minute.
“Newcastle played against Leeds. They won it at the last minute. So very hard games.
“And after those efforts to come here and play another 120 minutes, two teams that play a high tempo, demanding, physically way of playing. I suppose this has been an entertaining game. But they are the ones that they finish obviously more happy than us.”