Jayawardene was diagnosed with HIV in 1989 shortly after she moved to New Zealand from Zimbabwe.
She is using her struggle with the infection to become an advocate for HIV sufferers.
"HIV has become almost normal because of medication, and one of the biggest challenge is for people to accepting it as part of our society," Jayawardene said.
"In the rainbow community, I am disheartened at how many of us had committed suicide due to despair."
She knew of seven who had taken their lives in the past year.
"Those of us with HIV suffer a double discrimination, not only for being gay but also for having HIV," Jayawardene added.
"Discrimination is the biggest killer, it prevents people from coming out of the closet and they suffer more when they can't talk about it."
Jayawardene is working to make part of her Mt Roskill home a temporary refuge centre for people with HIV/Aids needing help.
The community was calling for political commitment and investment to support the drive to end infections.
There are about 3200 in NZ estimated to be living with HIV, and gay and bisexual men continue to be most at risk.
Eight in 10 of the 109 infected with HIV in New Zealand in 2015 were either gay or bisexual.
The theme for Sunday's NZ Aids Foundation-organised Big Gay Out at Coyle Park is "Ending HIV".
According to the foundation, NZ has a low HIV prevalence compared to global trends largely due to high levels of condom use here.
The Ending HIV campaign aims to maintain the level of condom use, make preventive medication more widely available and increase testing to find undiagnosed HIV infection.
"HIV is most dangerous when you don't know it's there. With HIV on the rise, getting a sexual health check-up at least twice a year is a must for high risk individuals," said Jason Myers, the foundation's executive director.
"HIV is no longer a death sentence, it's a serious, but manageable, health condition."
This year's headline artist at the event is Paron James, an acclaimed singer and songwriter from the United States.
The line-up of local acts include Openside, Lavina Williams, Cindy of Samoa and crowd favourite Miss Ribena.