Oscar winner Charlize Theron fought back tears during a recent trip home to South Africa when she saw the mobile AIDS testing and counseling clinic her cash had created.

Theron teamed up with Oprah Winfrey’s Angel Network to create a much-needed new health and educational resource in Kwazulu-Natal. The actress returned to her homeland to shoot a short film about the mobile health unit, which travels between remote high schools and services more than 3,000 students who have lost family and loved ones to AIDS.

In the film, which aired on Winfrey’s show on Monday, Theron is seen chatting to kids, handing over gift bags and helping them with AIDS tests, but it was one encounter with a young girl who recently lost both parents that upset the actress.

She says, “To see kids be able to talk that way with each other, with an adult, with a counselor, that never happened when I grew up in this country. It’s hard because part of me feels incredibly blessed in my life and then you come here and you see people struggling, and then you see this beautiful thing which is the spirit of these people and how resilient they are and that’s the miracle.

Theron also offered the high school students advice about condom use and told them about how she learned to become a better person by her own late father’s mistakes. And Theron was holding back tears again when one young South African girl told her she’d “awakened” her dreams of becoming a businesswoman.

She told Winfrey the whole trip made her feel so lucky: “Those kids have a 50 percent chance of contracting HIV and AIDS and dying from it, and that could have been my life.”

WENN