Yes, this kind of thing is tough. I have been through similar twice, once with a former best friend and later with a family member.  Both of those I managed to get close to, the best friend before he became ill. In fact, he died suddenly, getting out of his armchair to retrieve an errant TV remote - 50 years old! All these years later (19 and counting) I keep thanking my lucky stars - or who/whatever - for our chance meeting in the company of other mutual friends. In retrospect though that is one of the happiest days of my life, still after all this time.

The other was more prolonged, a lingering illness with a lot of handwringing and such, eventually ending with repeated hugs of forgiveness, and for some time - several months actually - before the eventual unavoidable outcome.

Sometimes I wonder how I could or would or if I could or would forgive myself had I not been so fortunate - twice. And I do consider it fortunate, despite the losses of two such close and important beings.

My heart goes out to you in every way!