Beverly Hills 90210 and Charmed star Shannen Doherty is trying to stay positive after being diagnosed with breast cancer as she thanks the support and love of the people around her that is giving her strength in her latest battle.

"Yes, I have breast cancer, and I am currently undergoing treatment," she told PEOPLE Magazine in an interview. "I am continuing to eat right, exercise and stay very positive about my life. I am thankful to my family, friends and doctors for their support and, of course, my fans who have stood by me."

She also wrote on her Twitter account, "Thank you for all the love and positive energy. It means the world to me. In case I don't tell u all enough... Love you."

The 44-year old actress was forced to come out in the open about her disease after entertainment web site TMZ revealed that she has filed a lawsuit against her former business manager, Tanner, Mainstain, Glynn & Johnson, which she accused of mishandling her finances and failing to pay her insurance premiums that caused her coverage to lapse.

In her lawsuit, she alleged that the management firm did not pay for an invoice of her insurance premium in 2014, resulting to the cancellation of her insurance coverage and prevented her from re-enrolling in 2015. Shannen said she was unaware that her insurance had lapsed and she did not regularly visit her doctors during the lapse period, a practice she usually does.

However, her doctors diagnosed her with cancer after they discovered that she "had invasive breast cancer metastatic to at least one lymph node" and "was informed that her cancer had spread during 2014 (when she was uninsured)."

Shannen told the court in her lawsuit that had her health insurance had not lapsed, doctors could have detected the cancer much earlier as she would have regularly visit them and she would not have to endure the possible treatment of chemotherapy and mastectomy.

Since the discovery of her cancer, Shannen said she has not been able to work and has accumulated "significant" amount of medical expenses.

One Hollywood insider commented, "Her finances were not handled by someone she trusted handle them. This was someone she trusted."

A representative for Tanner Mainstain issued this response to PEOPLE, "Tanner Mainstain is saddened to learn that Ms. Doherty is suffering from cancer and wishes her a full recovery. However, the claim that Tanner Mainstain caused her to be uninsured, prevented her from seeking medical care, or somehow contributed to her cancer is patently false. Tanner Mainstain will aggressively defend all of Ms. Doherty's claims in court."

Shannen is married to photographer Kurt Iswarienko. She is best known for her roles on the hit '90s TV show Beverly Hills, 90210 as Brenda Walsh, as Prue Halliwell in Charmed and Heather in Heathers.