The 41-year-old posted screen grabs of messages she claimed were found on 24-year-old Tom's phone to another woman.
Danniella wrote: "Once a cheat always a cheat !! Thanks Tom for being a cheating money hungry fame hungry 2 bob mug! [sic]
"When you find out at your darkest times he's been seeing someone else for months. Tom Richards is scum beware girls."
"I seriously hope the guy that's fighting @OfficialTomRich this week end beats the cr*p out of him. Knock him out for me. Cheating scum bag [sic]."
After getting together early last year, Danniella and cage fighter Tom, went through some tough times together.
The former EastEnders actress suffered a miscarriage early on in their relationship, they got engaged and split up and Danniella revealed she'd relapsed and was taking cocaine again. Money troubles also resulted the mum-of-two being made homeless.
Tom tried to redeem himself with a public apology. He wrote: "I'm gutted. I've lost my girl. I've broken her heart. Danniella, I'm sorry. I messed up."
But it seems Danniella is finally putting herself first as she gets back to work. She later tweeted: "Very productive days meetings with @celebagents in London. excited to be going back to work #newstart [sic]."
EastEnders, children, addiction and kidnap: The highs and lows of Danniella Westbrook
1 of 26Danniella Westbrook
She's one of the most controversial stars of the last decade and Danniella Westbook's life could be something pulled straight out the soap that made her famous. From the immense highs to the dark lows, here's her life in pictures.
2 of 26danni3
40-years-old, born 5 November 1973.
3 of 26danni4
She is originally from Walthamstow, London but she grew up in Loughton, Essex.
4 of 26danni6
She attended the Sylvia Young Theatre School, alongside Denise Van Outen and Emma Bunton.
5 of 26danni7
Her first job was modelling for Asda when she was just seven. She continued modelling for brands including Next and Coca-Cola.
6 of 26danni8
Her first job on albert Square was actually when she was 11-years-old, when she appeared as a roller skating extra.
7 of 26danni9
A local newspaper ran the picture of her as an EastEnders' extra with the caption: "who knows, one day she may be the show's star".
8 of 26danni10
She made her debut as Sam Mitchell on EastEnders when she was just 16, in 1990.
9 of 26danni11
Her soap fame led to her regularly using cocaine on the London club scene.
10 of 26danni12
She dated singer Brian Harvey until 1995.
11 of 26danni13
Danniella's addiction to the Class A drug started to affect her work and EastEnders terminated her contract in 1996.
12 of 26danni14
By the time she was 21, Danniella was spending £400-a-day on her addiction to cocaine.
13 of 26dannikai
While pregnant with her first son Kai, Danniella was taking 5g of coke a day.
14 of 26danni15
In 2000 Danniella was pictured at the British Soap Awards with her septum missing.
15 of 26danni16
Six months later she entered rehab for the first time.
16 of 26danni17
In December 2001 Danniella married businessman Kevin Jenkins.
17 of 26danni18
She gave birth to their daughter Jody B three months earlier.
18 of 26danniimaceleb
Danniella took part in the 2003 series of I'm a Celebrity…Get Me Out Of Here!
19 of 26danni19
Following her stint in the jungle, Danniella moved to Orange County, California and claimed she didn't want to be a celebrity anymore.
20 of 26danni20
In 2009 Danniella returned to EastEnders temporarily.
21 of 26danni21
She and her husband and children moved back to the UK permanently in 2011.
22 of 26danni22
Danniella revealed last year that during the height of her addiction she was kidnapped and gang raped.
23 of 26danni23
She started dating 24-year-old cage fighter Tom Richards following her split from Kevin in January this year.
24 of 26danni24
In June Danniella miscarried her and Tom's baby.
25 of 26danni25
Danniella revealed in August that she had returned to drugs, admitting that she had split from Tom and slept with her dealer.
26 of 26danni28
Her dad Andy was a cab driver and her mum Sue was a shop assistant.