Is there something wrong with me that I'm having trouble caring for my aging parent?

I just feel like I’m missing some crucial gene or something. I’ve never wanted kids, and now that my mom (who lives with me) is failing, I’m having trouble coping in general, but particularly when it comes to “bathroom stuff”.
I know a lot of people have cared/are caring for elderly parents in their home, but I just don’t know how they cope. (And I did let my siblings know from the start that this was not something I could handle.)
Problem is, now I’m feeling like there must be something wrong with me, but I can’t understand it. I’m very compassionate and empathetic, so why can I not handle this? Even listening to her talk about her pain constantly (which she won’t talk to her doctor about and blows off when talking to other people) is becoming intolerable.
I think part of it is that emotionally it’s tearing me apart to see her in this state. I’m not naive, and yet, somehow I pictured my mom getting frailer, getting weaker, but staying mentally sharp. I think dementia may be starting to set in, and I feel very ill equipped to deal with that.
There are other siblings. One is busy with her own family and only comes over occasionally. One is so busy with her work that she is very limited in the time she can give, and my brother lives an hour away and just wants to have “meetings” over the phone about stuff. (And this was well before the coronavirus.) Nobody else is living with her 24 hours a day, and I’m getting frustrated.
One good thing…we called the doctor today (as things have gotten a lot worse the past few days), and she is having a nurse come out starting tomorrow to do blood work, urine test, other vitals, etc. But…I am not sure how often she’ll come.
It’s bad when you just want to pack up your car with your essentials and your cats, drive far away and never come back.