Working 60 hours a week and relationships.

I’m mostly doubting that I’ll ever achieve a good work-life balance.

It is a lot easier when you do a lot of work at home. You have to get it done, but you can schedule it over parts of weekends and stuff. I don’t even count time I spend at home doing work stuff as work these days.
I think your situations is sustainable. Barely, but possible.
Just don’t have kids and try and keep it up.