Tottenham lost four players during the winter window, with Dele Alli, Bryan Gil, Tanguy Ndombele and Giovani Lo Celso all departing the North London club.
Spurs also brought in Juventus pair Rodrigo Bentancur and Dejan Kulusevski but missed out on Luis Diaz and Adama Traore, who joined Liverpool and Barcelona respectively instead.
Tottenham have lost their last three Premier League games and visit champions Manchester City in their next Premier League game.
They have dropped to eighth on the league table.
"It's always difficult to make comparisons, but if I had to find something similar, it would be the lack of confidence that is inevitable when you start work at a club that hasn't won in a long time," Conte told Sky Italia in a candid interview.
"I saw some situations from the outside that could be developed, but when you get into it, you realise that something… "What happened in January was not easy.
"We lost four players in January. Four important players for Tottenham, and we brought in only two. So even just in terms of numbers, rather than reinforce the squad, we on paper weakened it.
"Bentancur and Kulusevski are ideal prospects for Tottenham, because Tottenham are seeking young players they can develop and grow, not players who are ready. That is the issue.”
