Cleveland has lost 15 straight regular season games and has not won since Week 14 of the 2015 season.
"Being 0–12 is probably ... the hardest thing ever," Jackson said. "It's been a long 12 weeks."
Tears welled in Jackson's eyes and his voice broke slightly as he shared his feelings on having the NFL's worst record, according to ESPN.
Cleveland is averaging 16.8 points and has allowed every opponent this season to score at least 24 points.
Jackson, who is in his first year with the team, said he isn't worried about his job security.
"I'm going to be here," Jackson said. "I don't like losing. I never have and never will. I've had my butt kicked up over my shoulders enough this season that I really don't need my butt kicked anymore."
Despite the struggles, Jackson said he has belief that the team will turn their fortunes around.
"I told our players, and I mean this and I'm going to tell all of you: This will be the last time, this year, that we ever feel the way we feel," Jackson said. "I know that in my heart. I know that without question."
Cleveland is off this week and next plays the Cincinnati Bengals on Dec. 11.
– Scooby Axson