Is an ending that deeply affect the writer good?

I have had this novel idea in my head for 3 years now, and just recently I've decided the ending should be a bitter sweet one.

And while I genuinely, from the bottom of my heart, don't want it to be the best ending I've come up with, I can't in good faith act like it isn't.

The story is essentially that of a girl who wants to have a meaningful relationship with her family, but due to cultural and familial pressures, she receives the opposite. When she becomes an adult, she's both met and rebelled against these pressures and it leads to even more conflict with her family, to where they push her away succesfully.

The bittersweet part is she has a terminal disease, and the family only finds out when she has months left, and they waste most of that time trying to find a cure. The ending chapters would be the last month, where after many failures, the family and the MC get to spend a few happy weeks, before she dies.

I want to give her a happy ending, I well and truly do, but I don't know if I can make one as impactful as this one. The moral of my story, I think, is that it doesn't matter how different someone's life or person is from yours, you shouldn't push them away based on that.

This ending really gives me genuine heartache, I know part of it is because of how long I've been with these characters, but the ending is so devastating for me--is it a good ending in itself?