Oh god, I feel for you. My first job had the workload from hell, and yes, you need to get out. Am assuming 30% research is a (un)funny joke.
Your marking workload is quite shocking. Apart from anything else it suggests to me that you don't have a proper mix of assessment modes - is it all coursework? No exams? No practicals or presentations that get marked "in the room" as it were?
For a start you should NEVER mark up more than one draft, and if you mark up drafts you should not mark up the final submission. We are notorious in my institution (top end Russell group) for giving feedback on drafts as no other department does this - just marks final submissions. And we have lots of international students with less than excellent English too.
Actual research on higher education is your friend here. There are proper academic studies out there that say that students do not read markups on final submissions, only drafts, and only take in three pieces of feedback on a feedback sheet. This should help reduce your load.
As for personal tutorials and academic tutorials, be absolutely rigorous about doing everything by the book and not one thing more on the grounds of fairness to all students. Call your personal tutees in for tutorials and hold them all back to back in one block so that you control the time. Same with dissèrtations and any other one-to-one teaching - schedule it all in one day, all back to back.
And refuse to see students to give them personalised help on academic work outside the assessment framework. This is on the grounds that if you give one student what amounts to an individual academic tutorial you will have to give this to all of your students on grounds of fairness - and you LITERALLY don't have time. My students have ALWAYS understood and respected that logic.
Finally, be rigid with your preparation and teaching time. Set aside one of the five working days as a research day and go to the library/get away from email and distractions. Use Saturday as a second research day. The other four days have a rigid 9-5 routine - do not do any teaching or admin or emails outside these hours.
And practise saying no.