A popular blogger has been calling Tessica Brown — aka, ‘Gorilla Glue Girl’ — a bold-faced liar who made the whole saga up and scammed the world … but Tessica is now saying she better shut it, or risk getting dragged into court.

An attorney repping Tessica’s management team fired off a cease and desist letter to one Ashley Germon — who appears to run the IG and Twitter accounts @gossipofthecity_ — telling her to stop spreading the claim TB hustled everybody into thinking she sprayed Gorilla Glue into her hair.

Germon’s been posting about it for several days now, including messages and videos to both accounts — which have close to 610,000 combined followers — insisting Tessica is a liar and that she pulled a fast one … especially on those who donated money to her.

She even re-posted a 15-minute video from another woman who claimed to have sprayed Gorilla Glue in her own hair, trying to debunk Tessica’s account. Germon writes of that woman, “Salute to this sister who actually deserves the money y’all donated to that liar. #girlbye.”

Germon even acknowledged the cease and desist in a separate post, calling it a fake. We’ve been assured by Tessica’s team, though, that it is very much real … and they mean business.

Now, Tessica herself detailed the pain, embarrassment and agony she was going through with us directly and insisted this was as real (and unfortunate) as one could imagine. Remember, she went to the ER over this, and even flew out to Cali for a procedure to remove the adhesive.

Yeah, something tells us she’s telling the truth … hard to believe anybody would go through all this for a gag.