His side crashed out 1-0 at the Conference side as The Whites progressed to round two thanks to Stefan Payne’s goal in first-half injury time.
It was a new low for the Shrimps on their recent poor run of form.
Bentley said: “It’s the lowest I’ve been as a manager.
“We’re not having a great time at the minute and haven’t won in three before today but in the FA Cup a couple of sticky performances goes out of the window.
“It wasn’t a great pitch to play football on, the wind was up, it was a typical cup tie with the home supporters right behind their team and it was a battle.
“I thought we battled quite well but we didn’t choose the right ball in the final third enough and when we did get in the ‘keeper made a couple of good saves or we just didn’t have the rub of the green in the box.
“When it comes up to half-time as a defence you’ve got to make sure you’re strong and see it through to the interval but I was disappointed with our defending for the winning goal.
“We got turned too easily and the lad’s put it in the back of the net.
“We huffed and puffed, had chances here and there but goals change games and they got the all important one.
“They got the momentum, they got the confidence, they got the crowd behind them and we were chasing the game.
“I’m absolutely devastated and our fans had every right to have a go at us as we went off the pitch.
“I’ve not had that as a manager but I take it on the chin.”
Bentley paid tribute to the Morecambe fans who made the near 700-mile round trip only to see their side put in another disappointing display.
He said: “Our fans were superb today.
“I didn’t expect as many to travel as did and we’ve let them down today.
“They were dreaming of the third round and who we could have possibly got.”