Golden State captured their first NBA title in 40 years, beating the Cavaliers in six games.
James averaged 35.8 points, 13.3 rebounds and 8.8 assists in the finals, becoming the first player in finals history to lead both teams in points, assists and rebounds for the entire series.
Cleveland led the series two games to one before losing four straight.
"I guess there's nightmares now about situations throughout the games that's always replaying in my head," James said to Bleacher Report Radio on Sirius XM. "It's definitely difficult, you know I'm getting better every day, but you know it takes quite a while for me to get out of the funk."
James says his three children help him so he won’t stay in a funk too long.
"I got these three kids running around this house every day that don't allow me to not be happy," James said.
Irving missed the last five games of the series with a knee injury and Love was injured in the first round playoff series against the Boston Celtics.
"If we had our two All-Stars in the lineup it gives us a better shot," James said. "Does it say we're gonna win the championship? Does not. You've still got to go out on the floor and play the game, but it definitely gives us a much better shot than we had."
"I can't remember [any] team in NBA history, and I'm a historian of the game, that was able to get as far as we did missing two All-Stars,” he added.
James declined his $21.6 million player option for next season and signed a two-year, $47 million contract to return to the Cavaliers next season. He will make $23 million in 2015-16, with the deal including a $24 million player option for 2016-17.
- Scooby Axson