Spurs held a 3-1 lead going into the final 15 minutes but failed to hold on as Theo Walcott and James Ward-Prowse scored to give the Saints a share of the spoils.
In a matter of weeks, Tottenham have been knocked out of the FA Cup by Sheffield United and were eliminated by AC Milan in the UEFA Champions League on Tuesday.
They are now fourth on the Premier League table, two points ahead of fifth placed Newcastle United, who have two games in hand.
"The problem is we have shown we are not a team. We are 11 players," Conte told reporters after the game.
"I see selfish players. I see players that don’t want to help each other, that don't play with heart."
"The players don't want to play under pressure, don't want to play under stress. Tottenham's story is this – 20 years and they never won something. Why?" he asked.
"The fault is only the club or every manager that comes here? Until now I try to hide the situation. But there are 10 games to go.
"People think we can fight? Fight for what? With this attitude, this spirit, this commitment. For seventh? Eighth place? I am really upset."
"We are winning 3-1 [with] 15 minutes to go and I think you have to win.
"I don't want to talk about the technical aspect, the spirit is missing. We are not a team. We are a team where everyone is thinking of himself.
"When you are in this way that can happen, you lose against Sheffield United and drop [out of] the FA Cup and with Milan [in the Champions League]. 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. 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. The players go onto the pitch, I'm the coach, OK I take the responsibility, the players have to take some.
"What happened in the last period is unacceptable and I tried every moment to speak to try to improve the situation and to transfer the importance to be a team and to help each other, but I'm not seeing this."