Iorfa found the back of the net for the second consecutive away match, ghosting in unmarked to head home Barry Bannan's inch perfect free kick in the 57th minute to cancel out Bradley Johnson's first half opener.
The full-back said: "It was a relief because I wasn't happy with the first half and neither was the team. We were not at it. We were not great.
"It was good to get an early goal and I was happy I contributed a bit.
"For me personally, I wasn't that good in that first half as well so it was relief for me as you could see in the celebration when I got the goal."
It was Iorfa's fifth outing since moving to Hillsborough.
"I was not really that good on the ball today, especially in the first half when I was making silly errors and I really think I can be better in possession to help the team," said Iorfa. "I thought I did better in the second half.
"We had some chances in the first half but they were from Derby's errors. We played better as a team in the second half. Derby had their chances at the end and put us under pressure but I think we defended well."
Wednesday, sitting in 13th position, six points adrift of the Rams with 10 fixtures left to play, have yet to be beaten since Steve Bruce took over as manager eight matches ago.
Iorfa said: "The main thing is we didn't lose.
"They scored an early goal in the first half. We had a few chances but we weren't that great. We stuck in there and made sure we didn't concede again and we came out in the second half and gave it a good go.
"We all know how good a players we are and that we have to believe in ourselves.
"It is a good dressing room in terms of when we are not really at it. Everyone is honest and the manager is honest and I think that is how we are getting good performances."
The 23-year-old hopes to make his third start on the bounce when the Owls travel to lowly Bolton Wanderers on Tuesday night.
"I'm happy that I'm getting a run of games now," he said. "I want to keep on doing well.
"I'm happy I scored. Hopefully I can get another opportunity on Tuesday and kick on from there."