Worcester looked to be heading for their second draw of the campaign against London Irish before the hosts snatched a 23-16 victory with a late converted try at the Madejski Stadium.
It means Warriors are without a win in eight matches and are languishing in the danger zone in the Guinness Premiership.
A desperately disappointed Ruddock said: "I thought we deserved the draw but at times discipline cost us some silly penalties and the try at the end was heart breaking after such a big effort.
"It's the story of our season. If you look at most of our games we haven't been a million miles away.
"We haven't won yet but the scorelines haven't been massive against us and our effort today was absolutely huge."
Ruddock was also unhappy about the late Irish try scored by left-wing Sailosi Tagicakibau.
"I would like to look at it again as I believe there was some blocking of our defensive tackling," he said.
Ruddock gave recently-signed All Blacks Rico Gear and Sam Tuitupou, who scored an excellent try, their Premiership debuts and said: "This team has improved and we have added some quality players.
"If we play like that and cut down on some of the penalties we gave away, we will win more matches than we lose."
Toby Booth, the London Irish coach, said: "Worcester were a difficult team to beat."
Irish are hoping that England veteran Mike Catt, who missed the match after failing a morning fitness test, will return for Saturday's visit to Leicester Tigers.
Booth said: "Everyone knows how dangerous that game is. It's the only place we haven't won during my time here and we need all our best players fit."