The Glasgow scrum-half said: "I was crap. We were rubbish. If I ever get a chance to represent my country again I have to make sure I don't play like that.
"I didn't want to come out here and talk publicly about it but I feel you have to face it and take it on the chin. A lot of us performed below the level we expect and as a team we all take the criticism on the chin.
"I haven't played a game since April, I was getting hit off the ball quite a bit and having to dig the ball out a lot but that doesn't explain five or six poor passes.
"We said we would make no excuses and we shouldn't. Wales came out all guns blazing and we didn't have the answers.
"I am gutted to have the chance at last to make a Test start after waiting a long time and then to play like that."