Loss of companion

I lost my companion of 22years May 13 of stage 4 lung cancer. She fought for a year and a half through 30 radiations and over 15 chemo treatments as well as surgery to remove part of her colon as the cancer metastasized to the colon. She had a stoma bag for over 8 months. I am grieving the fact that she fought so hard and didn’t deserve that suffering. Besides trying to stay busy, are there any suggestions you can offer to deal with this terrible loss. Thank you.