United came from 2-0 down to draw 2-2, but survived an Everton penalty claim in injury-time, which was overturned by VAR.
Amorim said, "I think it was a soft touch from what I saw. I think it was a soft penalty, it was clear."
He also stated: "We need to win three points and we need to win the whole game. The worst part is that we are losing the ball without pressure and we are not doing what we need to do. We were soft.
"In training, we have to continue to do the same. In the second half, we changed nothing. We have to do the same thing but in a good way. We have to improve on creating chances and in this game also we struggle with scoring goals."
On what he can do to make his side more consistent, Amorim also said: "I don't know, if I know, I will change it. Everything we do in the week, we have to do better in the game. In this moment, we need to focus on day by day.
"We need to survive this season and then we can think ahead. I don't want to just say the negative part. In the second half, we were close to win this game."