Jon 'Bones' Jones Apologizes for DUI on Facebook -- 'I Screwed Up, Big Time'

UFC champion Jon "Bones" Jones says he's "truly sorry" for letting down his fans when he was arrested for DUI this past weekend ... saying, "I screwed up, big time."

TMZ broke the story ... the 24-year-old was arrested Saturday morning after totaling his Bentley in Upstate New York.

But yesterday, Jones reportedly posted a message on his Facebook page saying, "I screwed up, big time. Just needed to say thank you to all you guys for being amazing friends/supporters."

He continued, "Although the hell that will come with this hasn't even started yet, I want you guys to know how much better you've all made me feel, not only about this situation but about life, everything."

"It's good to feel that people are there and care. With that being said, I felt I should apologize to you first."

"I'm truly sorry to those of you that I may have embarrassed in any way, to those of you with kids that I may have let down. I will prove to them as well as to myself, that no matter what is happening in life, we can always work our way back and make things even better than before."