Background
My boyfriend of almost 5 years and I are living with my parents until we've found a house. We are both 25. I recently dropped out of university, but found a good job in my field. We both work full time. In fact, I work 8:00-16:30 and my boyfriend 7:00-17:00. I take him to work, which is slightly over half an hour drive from our home. My own work is another half an hour further and I pick him up on the way back home. So we leave for work at 6:15 and come back around 17:45. In the evenings, my boyfriend works on an online course he is enrolled in and I prepare for a new studies I am starting in 2019. My boyfriend also works Saturdays. We're planning to move out. We've been talking with housing companies and are ready to sign a rental agreement for a house currently being built, expected to be ready 6-9 months from now.
My parents have a relatively large house with a large garden and they own a dog. My mother works full time. She leaves at 5:00 and comes back at 14:30. My father used to work full time, but got muscle damage in his arm, so he can't work right now.
I only recently started working, about half a year ago. Before that, I took care of the dog, walking it before my classes started. I did nearly all the cooking and washing up and laundry. I vacuumed every other day and dusted twice a week.
Since I started working and especially since my boyfriend took up this job where I have to take him to, I've got a lot less spare time. I get up at 5:30, leave for work at 6:15. I don't have time to do my makeup anymore, nor to eat a proper breakfast. It's just a sandwich and a quick wash nowadays. I get back from work at 17:45, start cooking (usually for 6 to 8 people), put dinner on the table around 18:15, have dinner for over an hour (because my parents think bonding time is important), do the washing up and get ready for my studies around 20:00. Sometimes we have to walk the dog for an hour instead, because my parents are tired and my siblings aren't at home, then we get home around 20:30. I work on my studies for about an hour to an hour and a half before bed. My boyfriend helps me with all tasks, sets up the table and does his own studies when I do mine. On the weekends, I try to spend time on studying, but also on earning some extra money through photography. I try to sell the photos I make. That works okay. The earnings are not as good as my software job, but they are slowly increasing. Sometimes I just spend time on increasing my social media presence. It's touch, but it works.
For some reason, my parents don't think I have a demanding job (I'm a software engineer). They think I am lazy and I've received comments about not starting to cook immediately when I get home after a particularly demanding day. I also get told that I need to do my homework (university stuff) more diligently, so I don't need to work on it for weeks, because my sister (who goes to secundary education) finishes her work in a few hours.
Problem
Later this week, my father is going into surgery. He and my mother have asked the kids (me, my boyfriend, my 21 year old brother and my 18 year old sister) to take over the household chores, since my mother works full time and my father cannot help. That sounds fair, I think. My sister says she can't help any more than she does at the moment, and my parents agree, since she goes to school 20 hours a week and works 20 hours and school is demanding. My brother has severe autism, goes to his job 30 hours a week and throws a tantrum when he has to do any chore besides walk the dog, so we've settled for having him walk the dog most of the time, except when he's with his girlfriend, which is about most of the time. The conclusion was: my boyfriend and I can do all the extra chores! Mainly me, since my boyfriend works in a factory and I just sit all day. So on top of my already incredibly busy schedule, I have to take care of the garden, dusting, vacuuming, laundry and shopping.
I'm starting to feel like some kind of Cinderella. Moreover, I am starting to fall asleep at work (not yet while driving, luckily). How can I bring this up with my parents?