I completely understand.
First, remember that the first year is absolutely the hardest. I remember my first project
(10 months long actually). It was HARD. But, things did get easier afterwards as I worked more efficiently, learned boundaries, etc. (i.e. what actually has to be done vs what doesn't).
Second, think about your long-term goals. 5 years from now will you be totally fine with having quit (and be in a good position both career and life-wise)? Or, would you be happier if you gritted it out for another 6-12 months?
If you can, I highly advise trying to get to the 1.5 year mark. Set a goal and work towards that.
Furthermore, take advantage of leave and other office programs to extend your time there.
Feel free to reach out. Happy to talk about this further...there's a lot you can do to make the going easier!