So frustrated with my mom

Sometimes I just want to yell because of how frustrated my mother makes me feel. These past few years I've tried so hard to make a change and be more understanding but I fucking cant. During this whole pandemic thing I still have to go to work. I only get two days off. So I ask her if we need to go to the market to let me know so I can go EARLY because I want to avoid lines. She said no then proceed to tell me yesterday to take her to the market mid day. I still took her even though there were big lines and all she could find were eggs. Today I wake up I and she asks me to take her again. I said okay even though theres things I want to do/ need to do before I go I to work tomorrow. Literally all I asked was if she was almost ready and what she needed me to get and she lost her shit. Sayingnim exactly like my dad always rushing her and that she cant think under all this stress. She makes me wait an entire hour while she gets ready just to come out in her pjs clothes again saying shes not going and is mad at me. I'm so tired of this childish behavior. She always does shit like this. When she was working and I'd pick her up I would always ask her what time shes out and I'm always out there waiting an extra half hour to two hours until she comes out. It pisses me off because she always gets pissed st me if I'm like 5 minutes late but shes never out on time. I'm sorry I know you're family but my time is fucking important too. Idk what to do at this point I literally want to pull out my hair. Anytime shes upset or mad we cant talk about it and if I try she says I'm going to kill her because she'll have a fucking heart attack or some shit. She can never stand confrontation. I understand sometimes I do give her attitude but she takes everything to heart. It doesnt matter whether I ask in a nice / calm voice if shes almost ready. I'm just at my wits end and dont know what to do.