Charlie Sheen -- Twitter SUCKS!! I'm Signing Out FOREVER

6:00 AM PT -- Charlie posted a final tweet around midnight ... saying, "reach for the stars everyone. dogspeed cadre. c out."

Charlie also tells TMZ, “Thank you all for your amazing support. Trust me when I say please ‘follow’ me to my next endeavor. It’s gonna be epic.”

Charlie Sheen is about to give nearly 8 million people a giant kiss-off -- he's shutting down his Twitter account ... TMZ has learned.

Sources close to the former warlock say @charliesheen will close up shop within days, or possibly mere hours ... because Charlie feels like he's not getting anything out of the social network. No offense to his 7,707,791 followers, we're sure.

Charlie started his Twitter page on March 1, 2011 -- back in his crazed "winning" days -- and attracted more than a million true believers in 48 hours. For the record ... his first tweet was a pic of Charlie with his then-goddess Bree Olsen.