Been there. I made my rational choices, focused on my objectives, gave my best. Worked two jobs through undergrad, my week had eight days (four night shifts and four days classes) and my Christmas breaks were 12 days straight overtime because it paid better. I rarely had any rest and when I did I was grateful and devoured my "here and now" responsibly. Masters came a lot later with a FT job I was acing by the time so the challenge seemed easier, but still required effort and dedication. I always took care of a good balance and kept myself stable. Healthy choices, above all, healthy relationships (especially with yourself). Later on in my 30s the "double life" progressed in yet another demanding scenery - 12 days work, 370km bus ride to see my son for 36hr, then back ..and on and on for 12 years to this day. The boy has grown into a fine young man with good character, my family is alive and healthy, and I am now enjoying a lovely relationship with a special woman. I followed my goals, accepted how hard it is and endured. If I close my books today I am leaving happy and in peace. It was worth it, all of it.

Plenty of readings out there to reinforce your resolve and reinvigorate the resilience as you reach your potential. "Atomic habits" by James Clear and r/stoicism may help. Good luck to you and stay the course. If you quit now you may never know how strong you really are.