My partner didn't die but it felt like it.
I was married 20+ happy years to my ex who has been physically disabled since birth.
Unfortunately about 10 years ago she developed estrogen receptor positive breast cancer I had found the lump one night and it was tiny 2.3mm in size she said it was probably a pimple and she wasn't that worried about it but something about it didn't feel right and I made her get it checked out.
10 days later they were going to do surgery and she was wanting to opt for a lumpectomy but for her surgery was quite a serious thing as due to her disability and her spine being shaped like an S in both directions and anesthesia was extremely risky, with a bit of convincing she finally opted for a full mastectomy of the breast which we found later was very lucky as there was a 2nd more aggressive tumor 30mm outside the margins of the first which as it was had already increased in size by six times.
I quite my job at this point and dedicated myself to looking after her, she had so many tubes coming out in all directions that she couldn't even roll over in bed. I moved myself into the spare room and slept on a foam mattress on the floor, mainly for her sake but partly for mine too as she now snored like an incoming artillery shell.
Chemotherapy then began and after 13 weeks treatment oddly enough without any side effects it was over ... or so we thought.
One Sunday night we were sitting having a cuppa and she began to feel light headed, she lost strength to the point she couldn't lift her cup of tea and she began to feel very tired, she wanted to wait and see if she felt better in the morning but i wasn't having that something wasn't right so into A&E she went, the end result was that the Chemotherapy had damaged her heart and she was in heart failure, if we had left it until the next morning as she had wanted she wouldn't have survived.
Medication for her heart was was provided and she was also put on Estrogen blockers at this point and slowly she regained her strength, but it still wasn't over.
Five years after the initial diagnoses pre cancerous calcification's were found in her other breast and this cycle barring the chemotherapy had to be repeated, she recovered slowly but over the next four years she began to change from the sweet loving lass that I once new to a hard callous person who only cared about what she wanted, when she wanted it and it didn't matter how she got it.
I had helped pay for her to go to Australia for a holiday that year and she did seem a little better after she returned ; however it turned out not to be from the holiday itself but what she had planed.
Three months after she had bee on the holiday one night just before christmas after I had finished cooking tea and was doing the dishes she informed me in a rather matter of fact tone.
"Since I have had cancer my priorities have changed, I want to live on my own, do what I want, when I want and not have to consider you, I have taken out hire purchases and gotten all my own stuff, I don't love you anymore and I'm leaving"

Needless to say I was gutted, I didn't want gratitude for what I had done for her because that's what you do when you love someone. I had however saved her life three times, gone through enumerable problems myself including suffering diabetes and curing myself of it over this period of time and a severe accident but I didn't expect her to be grateful but I felt like i deserved a little more respect than I got for what I had done.

Anyway that's my story - so I didn't loose my now ex-wife in the life sense but I did loose her.