The game had appeared set for a draw after Shrimps substitute Jack Redshaw cancelled out Lewis Montrose's first-half opener.
"To get beaten in that manner in injury time after the work rate we put in was devastating," said Bentley. "We played some good stuff. The substitutions worked well, and Jack put the ball in practically with his first touch
"But after that they threw a lot at us, but we defended our set plays well and when we did get the ball we soaked up the pressure and worked one or two very good chances. It can happen and when you switch off for a second you can get punished, which is what happened for both goals.
"We gave a very good account of ourselves and I hope it doesn't take the wind out of our sails as we've been playing really well of late.
"Although we've got a small squad for this level we really pushed and almost made it count. I'm really sorry for the fans who made such a long journey down here something to shout about."