Wolves lost by a four-goal margin for the first time under the Portuguese, with Jarrod Bowen at the double while Tomas Soucek and Sebastien Haller also got on the scoresheet at the London Stadium.
The result made it back-to-back defeats in the Premier League - and three losses in a row when counting the Carabao Cup exit to Stoke - and Nuno said: "It was a very bad performance, a bad game.
"Defensively, we were not good at all. We were unbalanced, disorganised, out of time and losing duels.
"Offensively, we didn't create. We were unable to break West Ham.
"Every time West Ham went for an attack, it was a chance at goal.
"In the second half, when we wanted to go for it, we still had the same problems.
"It's very disappointing on that aspect, all the game was very bad."
One of the worst performances since Nuno took charge in the summer of 2017 saw Bowen open the scoring after Wolves failed to react to a quickly-taken free-kick.
Bowen then made it two from close range in the second half before both Soucek and Haller, both unmarked as well, headed home.
Nuno is now determined to put things right against Fulham at Molineux on Sunday.
"It was very bad. It was a very bad game. We have to look at it. There are things we should do better," he said.
"Everybody knows our idea. Our foundation is being compact and solid, and we were not.
"That creates a lot of problems going forward in the game. If you're unbalanced and not able to sustain West Ham attacks, you cannot feel confident and positive to attack.
"So, we must improve. That's the only way to look at it. We have to work hard on the training pitch so we can improve.
"This is how we can bounce back, with hard work and sticking together.
"We know we have to do things better. The problems and solutions are inside, we cannot look outside. The problems and the solutions are inside of the squad."
Daniel Podence and Fernando Marcal both missed out through injury in the capital, with shoulder and calf issues respectively.
Marcal was not expected to be involved but Podence's absence came as a surprise.
Providing an update on his condition, Nuno added: "It was from the previous game and he was not able to recover. Let's see if he improves.
"Hopefully, he will start training during the week."