I am feeling the exact same at the minute! I worked hard at a level and was expecting the uni workload to be similar. I just feel bad because everybody says that uni is less stress than a levels. I am working all day 8am-11pm, similar to you, with a quick lunch and dinner I eat at my desk. When I decide to go to bed I feel awful because I still haven’t finished all of the work on my to do list. If I think I have done everything my lecturers have set, I log on to my unis online portal and find that even more pre-work has been added. I have a seminar tomorrow which I had to: watch 1h 30min documentary, 2h film, both with extensive notes and questions to be tested on, 2x2 hour lectures to watch and make notes, an essay, 46 pages of pre-reading and to plan my coursework. All for one module with 1 days notice, despite me having online classes in between that!!!