River prevailed 2-1 on aggregate in the Superclasico semi-final despite slipping to a narrow second-leg defeat at La Bombonera following Jan Hurtado's 80th-minute goal.
The holders will now face either Flamengo or Gremio in their bid to win South America's top continental competition for the fifth time.
River defeated their bitter rivals in last season's final, the second leg of which was moved to Madrid following an attack on the Boca bus.
"It is hard to analyse this match because I cannot deal with all this happiness," Gallardo said.
"It is hard for me to analyse the game and its development. I feel hugely happy for my players. I am so full of joy and happiness for our fans, who must feel really happy because we are going to play another Libertadores final, eliminating Boca once more.
"I cannot deal with all this happiness I feel right now, so I will give my insights about this game later, when I get able to do it more calmly."
Kick-off in Buenos Aires was delayed by 15 minutes due to excess confetti on the pitch but there was otherwise none of the fan trouble that marred last November's matches.
Gallardo saluted both sets of supporters for keeping the occasion free of trouble.
"I think we should appreciate it," he said. "This should be something natural to happen. As far as I know, there were no incidents to regret, either on the pitch or inside the stadium.
"This coming after the last time and all the damage it caused on us as a society, we must appreciate it.
"It should be normal, it should be natural. Achieving this game without any incidents is something we welcome. It means we learnt from it."