Following the game, Conte hit out at the players for the way they have failed to deliver throughout the campaign in all competitions.
"I'm really upset because this is not the first time and I think today I can tell you that this is an upset because we are winning 3-1 and 15 minutes to go and I think you have to win," Conte told BBC Sport.
"Instead we showed this another time, things started to improve last season but we lost the characteristic of last season. I don't want to talk about the technical aspect, the spirit is missing.
"We are not a team. We are a team that everyone is thinking of himself. When you are in this way that can happen, you lose against Sheffield United and drop the FA Cup and with AC Milan and to finish that run you're winning 3-1 and the last 15 you are able to give them the possibility to come back. I don't see the sense of responsibility of the players.
"Now it's difficult -- we are working hard with this group and to move in the right direction. We are going behind, I see a lot of negative situations and a lot of selfish situations and players that I don't like. I know the way to beat teams, in the past I beat a lot of teams, winning teams.
"Now instead we are going behind, no one is interested in this. I have great frustration about this because me and the staff stay every day to think of a way to improve. Honestly, it's time I have to take responsibility for me, the staff, the club but also the players."
Speaking in his postmatch news conference, Conte continued to show his frustrations with his players.
"Another time we showed that we are not a team, we are 11 players that go into the pitch, and I see selfish players, I see players that don't want to help each other, don't put the heart," he said.
"We are professionals, the club paid us a lot of money, the players receive money, me I receive money, do you understand? And not to find excuses, and not to have no spirit and show no sense of belonging, or sense of responsiblity.
"Because we are showing this, and for me this is unacceptable. This is the first time in my career that I see a situation like this. And until now I wasn't able to change, and compared to last season the situation went to become worse."
Conte also appeared to aim a dig at the club's ownership over the lack of trophies.
"They're used to it here. Don't play for something important," Conte added. "They don't want to play under pressure. They don't want to play under stress.
"Tottenham's story is this. Twenty years there is the owner and they never won something. Why? The fault is only for the club, or for every manager that stay here. I have seen the managers that Tottenham had on the bench.
"It is time to change this situation if Tottenham want to change. If they want to continue in this way, they can change the manager, a lot of managers, but the situation cannot change. Believe me."
Conte's side face Everton after the international break on April 5.