'Selling Sunset' Nicole Young Gets Death Threats After Feud with Chrishell Stause

"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.

Sparks flew quite a bit, with Chrishell even calling Nicole a "b****" straight to her face ... but despite all the anger coming her way, sources say Nicole's standing by her comments on the new season -- claiming not enough context was shown in the final edit.