Roberto De Zerbi said he and Tottenham had suffered until the last second of the Premier League season but described the club’s successful fight against relegation as the highlight of his career.Spurs recorded a 1-0 home win against Everton on a nervy and emotional final day to ensure they finished two points above West Ham, who went down despite beating Leeds 3-0 at the London Stadium.The Spurs defender Micky van de Ven said it was “embarrassing” that his club had been made to sweat until the very end but ultimately it was a day of relief and celebration.“I think this is the biggest achievement in my time,” De Zerbi said. “The Europa League at Brighton was great. The second place in Marseille, with a lot of problems, was a big achievement. But I think today was maybe one of the best days in football so far.“For sure, we have to learn from our mistakes. We are happy because we stay up and we forget the past. Actually, no! Stupid people forget the past. The smart people, the people with value, can’t forget and keep in their mind the past. We have to improve from our mistakes. And we are looking forward to start to rebuild a team from this night, from tomorrow. We have no time to go on holiday.“Will we be stronger for this? If we remember this day, for sure. Next season, we have to keep in our mind [what has happened], to give our best in every training session. If we remember this it will be easier.”De Zerbi considered what will be an important summer for Spurs. “We have not to change too many players,” he said. “We have 10, 11, 12 players who are good enough to stay – good enough as players and especially people. Then we have to complete the squad with the first-level of players because we suffer too much.“We are Tottenham and we can’t suffer like this until the last second of the last game to stay up. My target now is finished, to stay up. My [next] target is to start pre-season with the team in my dream, in my head.”Van de Ven said: “It is unacceptable that the last game we played this season we play for relegation. This club has some unbelievable players. It was embarrassing to let it come to the final day but we did it and that is what is important.“I was more emotional at the end. It has been a tough season for me personally, as well. I played almost every game and I have suffered a lot. The emotions are really happy and we must not let it happen again.”