Shannen Doherty spent her final weeks enduring the “hardest time” she had ever experienced with cancer. The ‘Beverly Hills, 90210’ actress lost her years-long battle with the disease on Saturday (13.07.24) and at the end of June told her A-list friend Katherine Heigl, 45, she was going through hell with the disease. She told her fellow star on her ‘Let’s Be Clear’ podcast: “I got cancer in 2015, and it went to remission, I think, right at the end of 2017 or at the beginning of 2018, and then it came back in 2019 as stage 4 breast cancer, but then it spread to my bones. And from there, it sprea…