Don't be sorry, J, it's better to process those emotions than to let them fester under some "social norm". You're only human, give yourself a break.

I'm so sorry for all that your mom is enduring, it's unbelievably difficult even when you are right there. I was, and I felt much of what you describe.

You've done all that is in your power to do for her and your dad, that says a lot.