Swans have lost their last four league games, including Wednesday's 3-0 drubbing by QPR and remain on 39 points - 10 clear of the drop.
Vorm said: "I had a good feeling before QPR but we gave a nothing performance.
"It was our worst game of the season and we got what we deserved. They scored before half time and I thought 'OK, we have 45 minutes to make things good'.
"But the second half was even worse. It's frustrating.
"I must apologise to the fans because they come and support us every time. We take 2,000-3,000 fans away from home and looked like we didn't care.
"Of course the players care but what QPR did looked too easy."