Thank you for your sympathies, and the compliment.
Regarding your situation, we each do what we can for the people we love. Unfortunately, life doesn't give us encounters balanced against our emotional, physical or financial capabilities. If you did everything you could bear to do, then you did enough. Wishing you could have done more is, I think, normal. Even in my situation, I wish there was more I could have done. I wish I could have spotted his decline earlier. I wish I could've been more motivating, and convinced him to keep doing the physical therapy he needed to not become completely bed-ridden.
And believe me, I did consider a living facility for him. However, he once told me he would rather die than go to one of those places. Also, we didn't have the financial wherewithal for him to go to one (they would have taken his pension and social security benefits as payment for his care, most of those places do that) without my becoming homeless. Fortunately, he had a bit of savings, and he always taught me to be frugal. Dad passed well before his savings ran out; from the time I had to leave my job to care for him until he passed was only about 5 months (the longest 5 months of my life, and likely of his as well, but that's a mercy compared to him hanging on for years). Had he outlived his savings however, the only option I came up with that would've obeyed his wishes was for me to shoot him (and then myself, because I'm not going to prison for doing the right thing).
I have chronic depression issues (and I've been intermittently contemplating suicide for the past 25 years, though it's been coming with more increased frequency over the past decade). My home situation at the time certainly didn't help my depression any, so I was ready to leave life behind if it came to that. I'm glad it didn't come to that, if only because I'm glad dad got to pass with someone he loved holding his hand and trying to say soothing things to him, instead of with a loved one pointing a .45 at his chest.
Once again my condolences.
You probably already know this, but in case you don't and you have a time when you are suicidal...I understand this is a National Suicide Line that you can call before you ever make a decision as fateful as that.
And not just you, but anyone, if you ever feel you are at the end of your rope or the end of the road and have nothing else, call before taking any drastic actions. I hope that somehow and someway you can feel better in the future and the suicidal feelings you have decrease in their frequency in the coming years.