This was me this time last year.
Working all hours, missing bed time with my kids for the first time ever. Kept flagging the workload to the directors but they just gave it the old slopey shoulders.
They want you to work so hard you run yourself into the ground because it costs less than hiring 2 people to do the workload properly.
I had two other people same seniority as me who were constantly saying they were too busy. Yet when it came to dishing out the new projects they would volunteer for the ones they fancied, but leave the shite ones to me. One had a conservation related qualification from years ago so took first dibs on the interesting projects, then immediately farmed it out to subordinates. Put daily meeting invites to themselves in their calendar to "keep up with emails" so that they looked busy on Scheduling Assistant.
They were all told, either you help me or I'm offski. Nothing changed, they didn't believe me so I handed in my notice.
I now only work my hours and don't volunteer to cover holidays etc. I have a professional qualification that allows me to mentor folk to get the same qualification but it's a huge time drain on me. My current employer sent a circular asking if anyone would like to mentor I just ignored it. Previously I would have jumped at the chance.
You need to switch employers and put in firm boundaries when you get there. The more you do the more it is just expected.
I'm lat 30s and almost had a breakdown last year. Now I'm incredibly happy in my new role.