I have days like this twice a week on average. Then a third day is mostly committee meetings, research seminar, etc, with perhaps an hour or two of unscheduled time in the middle. The advantage is that I can then have 1-2 days working from home which is bliss by comparison (if I’m not too exhausted to think straight by then)
That's pretty much my week - although at the moment my teaching is 4 days a week & I really have to duck & dive to preserve one research day. I work Saturdays in the library.
So I think that without the commute, that's a pretty reasonable workload, particularly if that's just 3 days a week. The only thing missing is that there are no real breaks - but presumably you could schedule PhD supervisions differently. Could you do emails on the train journey?
Obviously what's exhausting you is the 4 hours commute each day.
I did 10 years of a 2 hour each way commute. All by train, with a short local, then a 90 minute long distance (against the rush hour which meant I always got a seat). Some weeks I was there 6 days a week, some only 3.
I used to teach up to 9pm some weeks, but the university was pretty well set up for commuters, with a good connection to the mainline, and my rule was that if I was arriving back home after 8pm, I got a taxi from the mainline station home.
I got HUGE amounts of reading & marking & lecture prep done on the train: on the way to work (at 7:30-9am) I worked; coming home I read novels. No Wifi in those days to distract me!
I had one year where I deliberately managed to get all my teaching & supervision work into 2 days, then a third day for admin. The 2 teaching days were long, but then I usually had Monday & Friday not commuting.
But I would tend to sleep most of Saturday, and I certainly had to sacrifice the gym & the dance studio, and socialising other than weekends.
It can be exhausting. But it was my choice not to live in the (tinpot, claustrophobic) small town where I worked, and to stay living in the large city 100km away - that was where my friends, my family & my partner all lived. It was a great job (although ultimately, in the wrong country for me)