Paul Tisdale has blasted his defence after they conceded three goals again, this time to Swindon Town.
The 3-1 defeat at Stadium MK sees Dons drop out of the League 2 play-off spots for the first time since September, with big road trips to Newport County and Carlisle coming up this week.
Keeper Lee Nicholls should have done better with Michael Doughty's opener and Keshi Anderson's strike barely a minute after Jake Hesketh had given Dons a second half lifeline. Russell Martin took down Kaiyne Woolery with 18 minutes to go to give away a penalty, which Doughty chipped home to secure the win.
"We cannot concede three goals," said Tisdale. "It has happened too much in recent months. We're not not talking about it, but we have to stop it happening. We put a lot of fight into that, and we now have to go again on Tuesday.
"We're so disappointed with the results, but we have to go again and we have to show that fight again and pull us back.
"I'm disappointed we got caught on the counter, we spoke about it many times before the game, so that was, from my point of view, it's something I'd like to concentrate on.
"It's heartbreaking. We all know how it is to be leading away from home and to concede a goal. That next 10 minutes was ours and we gave it away in 20 seconds. I'm not sure what I can do about that. We cannot continue to make those mistakes."
Now down to eighth in League 2, outside of the play-off spots, Dons' dismal run has seen them pick up just seven points from a possible 30.
Tisdale continued: "We've had a run of results which mean we do have to mix our game up and have some energy that turns a game, pushes the opposition. We're all trying to hard, but you can get in a run where confidence goes a bit, and we're in that. I'd like to see more drive in the first 20 minutes.
"They have to channel their efforts in the right areas – we were waiting for things to happen in the first 30 minutes and probably got what we deserved."