I feel I'm not getting enough help from my SO and not sure how to ask

I started going back to school, which adds an extra 20 hours to my week away from home. To add, my dog recently went blind and, though she is adjusting, it takes a lot longer to walk her. The idea that my aging dog that has been in my life since I was 10 years old has caused me a great amount of stress. On top of school. On top of work. On top of the fact that if I don't clean, the apartment stays dirty. On top of the fact that if I don't cook, we have to eat out.

That being said, I wish my SO would help with some of the cooking and cleaning. That's it. I essentially work 6 days a week, so I feel I don't have time. The time I have off, I either spend with my SO, friends, and family, or I'm recharging the lost energy by doing things I enjoy. I do not enjoy cooking. I do not enjoy cleaning.

I feel it's not too much to ask my SO to clean when I don't have time, right?

I just don't know how to ask without my SO getting all huffy about it. I hate confrontation and I just want it to be like "Hey, can you clean the bathroom for me one day this week when you get off work" and then they're just like "Of course, whatever you need". Then they actually do it. But I know that's not how it's gonna go.

I'm just too stressed out to do EVERYTHING. Even the Christisan God needed a day of rest.