“Selling Sunset” newbie Nicole Young is feeling some serious fallout from her feud with costar Chrishell Stause — we’re told Nicole’s getting brutal death threats, now that their battle is out in the show’s latest season.

Sources close to Nicole tell TMZ … aside from the death threats, she’s been getting hit with meth addict accusations and loads of hateful speech from crazed fans — some of whom found her address and phone number.

Nicole’s been getting stuff like “Watch out on the streets….whores die,” “You’re a c***. A bully. I hope you die honestly,” and “No one likes you because you’re a crackhead. You should leave the O Group you f***ing methhead.”

Not only is she taking a beating, but we’re told folks have been calling out her family … and it’s now impacting her mental health. She’s backed out of appearances and podcast tapings because of the hateful reactions.

If you haven’t seen the new season … tensions got high after Nicole claimed Chrishell stole the credit for a listing they were working on together. She also claimed Chrishell was handed listings from head honcho Jason Oppenheim because they used to date.