Shareef O'Neal's heading to the operating table to fix his heart issue in December -- and his mom tells TMZ Sports she couldn't be more nervous for the UCLA superstar.
"I've been an emotional wreck, really. To be honest," Shaunie O'Neal says ... "I just really have. I still am. I'm just trying to push through."
We broke the story ... Shaq and Shaunie's son was diagnosed with an issue that will temporarily halt his hoops career -- and now that a date has been set for the open-heart surgery ... Mom says she's havin' a tough time.
"It's scary. It's scary no matter what. There's nothing anybody can say, do, tell me -- it's scary. And, I'm going to be feeling that way until this is over."
The good news ... Shareef doesn't seem too worried about the procedure -- telling us just a few weeks ago he's already planning for his life after the operation.
In fact, today he was goofing around on the basketball court in his Halloween costume.
As for Dad ... Shaunie says Shaq's been helping out families who have been put in similar situations as the O'Neals -- giving out iPads and even cash at the hospital.
Only a few more weeks until Shareef's on the other side of all this ... and we're all rooting for him.