Speaking to the club's official website after the game, Lambert said: "It's not great that's for sure when you lose a goal early doors at home, especially from a corner kick.
"We only had a twenty minute spell in the first half where we looked like ourselves and we had a couple of half chances.
"Then the second half there was a lot of endeavour but no creativity. The second goal was really poor, coming from a throw-in from Wigan.
"It was a hard one to take, that's for sure. It was disappointing because it was a chance for us to climb the table.
"Spurs are a really good side and so are Chelsea but we had an opportunity to pull away, especially at home, that's the disappointing thing.
"When you're competing with everyone else around you and you get turned over 3-0 at home, then it certainly hurts you, that's for sure.
"But you have to try and not let it fester, that's first and foremost. You have to put a stop to it.
"You have to keep their spirits up. You have to keep them believing and keep going. That's what you have to do.
"They will come in tomorrow and you pick them up again. There's two ways of going - you run with it and get going or roll over. We will keep on fighting.
"But the last three results have hurt us, no doubt about it because everyone was positive after the Liverpool game. But once three results go against you, there's a negativity.
"I understand that. I can see that. But I have the belief that Aston Villa will be fine."