Hugs Op. Take some time away and breathe. As pp have said some counselling will help.

I am trying to find fault with everything she did or does

Well, you become a better person than this! And you don't use the excuse that it's because you love her so much/will miss her.

You need a professional therapist, not DCUM

How old is your mom?

That sounds natural like upcoming college kids getting snappy with parents before they go off to school. It helps with separation. You’ve already identified your fear so try to shift your perspective so you can control it better. You’re fortunate to have an otherwise loving relationship with her. It’s really hard seeing parents decline so I get it.

Don’t let your fears of her impending death and the stress of caretaking rob you of the moments of beauty, joy, and connection you can still share.

I am a horrible person. My mom is the most important person besides my kids, in my life. She is declining and she’s not even old. Dementia, stroke. I am trying to find fault with everything she did or does because the thought of losing my beloved mom is so unbearable. Don’t know how to handle this.