Not always easy but we all have to try to do our best. Depending on what it is that you are dealing with, I find thinking that my mom can't help it, that it's her decline, not "her", in charge of her behavior, helpful to keep from getting overtly frustrated.
I find venting here and to a couple of close friends helpful as well.
Wish I knew. I have developed 2 escape behaviors every day. Doulingo ( learning French) and a word search app. Every day I spend at least 45 minutes on the French lessons and the word games. It does help. When the weather is nice, I take my almost 2 year old shepherd /husky on long walks. Doing something away from my mother does provide some sense of self or , jerks a memory of how my life used to be.
I find venting here and to a couple of close friends helpful as well.