Kim Zolciak was stunned when she received the rock-bottom score of 12 out of 30 on last week's "Dancing with the Stars."

The judging put her in an ignominious group of celebrities in "DWTS" history who have scored 12 or less.

But this Monday night, the former "Real Housewives of Atlanta" and current "Don't Be Tardy" Bravo reality star made a big dancing improvement with partner Tony Dovolani, earned a respectable 19 points, and survived the elimination round (Chaka Khan went home instead).

And to look oh-so-smooth for her quickstep, on Monday, brutally honest Zolciak told her fans on Instagram that she'd gotten injected with Botox!

Zolciak thanked Beverly Hills cosmetic surgeon Dr. Simon Ourian (best known for treating Kim Kardashian's stretch marks) and captioned a photo of the two of them together, "I needed Botox desperately lol."

After Monday's "DWTS," Zolciak elaborated to FOX411, "I had to get Botox. I needed it. So my doctor came in for me last night. He just had a baby two days ago [but] he came in for me."

But Zolciak, 37, also claimed it's not just for vanity--the filler has a therapeutic effect for her, "On a more serious note, it does help with my migraines. I've got it since I was 23 and so I’m at the 90 day mark—if I go past that, I end up in the bed with the migraines. I have to hurry up and get it but it works."

Zolciak said there's no sin in using Botox and feels other stars should go public about it: "I'm all for making yourself feel good. If you want to do it to feel good about yourself, do it. Why lie?  Why hide? We only go around one time so enjoy it."  

Zolciak's "DWTS" partner Dovolani told reporters, "I love…that she doesn't hide the fact she's had Botox."

The reality blonde smiled, "Oh, I don't give a s--t."

Still, using Botox had consequences on "DWTS": "I have so much makeup on to cover my bruises" from the filler, she revealed to FOX411 backstage.

On week two of the competition, the wife of Atlanta Falcons football player Kroy Biermann looked more than smooth on the dance floor, causing Judge Bruno Tonioli to rave, "She's alive! She's alive. It's the most unexpected comeback since Lazarus."

Zolciak said afterwards, "I feel so great. I really loved the quickstep. I wish it was my dance last week. I had so much fun. It was a big change for me to feel so chill and relaxed."  

Although rehearsal footage showed Dovolani getting irked about Zolciak dealing with texts and emails instead of getting down to "DWTS" business, it all worked out.  

In the understatement of the night, Dovolani noted, "We're stronger as a partnership this week."