Antonio Sabàto, Jr.'s calling it quits with his wife and the divorce is getting nasty ... with her making allegations of drug abuse as he launches a run for Congress.
The former soap star filed docs on December 27 to split from Cheryl Marie after a 5-year marriage. They have a 6-year-old son together and in docs, obtained by TMZ, she says she's concerned about the kid's safety due to Antonio's drug addiction.
Cheryl claims Antonio has struggled with prescription drugs ... specifically benzodiazepines -- a class of drugs that includes muscle relaxers, anti-anxiety meds and sleep disorder meds.
In her divorce docs, she says Antonio's admitted using crystal meth before they got together in 2009. She does, however, concede the birth of his daughter from another relationship motivated him to get sober.
Antonio tells TMZ ... he admits going to rehab for issues with sleeping pills. He's not trying to hide it, and says he's an outspoken advocate on addiction issues. However, he added, "Whatever else she says is just a bunch of lies."
A staunch Trump supporter ... Antonio filed docs last week to run for Congress and his platform will reportedly include dealing with the opioid crisis and drug addiction.
As for custody of their son -- he wants joint, but she's pushing for sole physical and joint legal.