My cat is sick

This cat is my life. She's 13 and she's been with me the majority of my life, she has always been someting constant and I love her with all that I have. She's had kittens her entire life and last year she nearly died giving birth. She had to get an emergency surgery to save her life and that already took out a lot from me emotionally and financially. And just as i thought all was well she got strange bumps on her stomach and now here we are again. She's currently in care at the vet but they aren't shure what's wrong. However they think she might have tumors and cancer. I don't know what I would do if she dies. This cat is my world and the bond I share with her is beyond my words. But my current financial status has me worried I might not be able to help her live and would kill me. I am begging for your help!