(Cover) - EN Showbiz - Shannen Doherty says the loss of her father was the worst thing she has ever experienced.

The 39-year-old actress was left devastated when John Thomas Doherty passed away at the age of 66 last month. Shannen admits she has been struggling to come to terms with her grief, although thanks her mother Rosa for encouraging her to move on with life.

Its really rough and definitely the worst thing Ive ever been through in my life, but my mom looked at me and said, Would your dad want you to be sitting in the house not trying to move forward? explained the star in an interview with Perez Hilton.

Shannen is currently promoting her book Badass: A Hard-Earned Guide to Living Life with Style and (the Right) Attitude, which blends self-help with her own life stories.

The star admits promoting it provides a good distraction from her mourning, and revealed it deals from everything from relationships to interior design.

Theres a lot of decorating tips, she laughed.

The actress is best known for her role as Brenda Walsh in 90s television show Beverly Hills, 90210, and she took time to discuss her former co-star Tori Spelling. The pair used to be close friends, and Shannen isnt sure why their friendship grew apart.

We were besties back in the day. I dont really know what happened, youre gonna have to ask her... she lamented. (C) Cover Media