NFL's Sheldon Richardson: I Know I Screwed Up ... But I've Changed

NY Jets stud defensive end Sheldon Richardson says he's not the same guy who was arrested earlier this season ... claiming he's seen the error in his ways and is now dedicated to helping others.

The former Pro Bowler took the mic at "Kevin Powell's 15th Annual Holiday Party And Clothing Drive" Tuesday night -- an event he put on with the former congressional candidate -- and opened up about his tumultuous summer.

"I was negative in the community ... I'm gonna change."

If you remember ... Richardson was arrested back in July for allegedly driving 143 mph in his Bentley and was also suspended for the first 4 games of this season for weed in a separate incident.

Check out the clip ... Sheldon says he's dedicated to putting all that behind him now ... and even pledged $5,000 to help homeless people in NYC.