Employers will take everything you're willing to give. You have to set boundaries. I used to work twice as hard over a weekend to meet a deadline. I then worked with people who, confidently, stated "Sorry, If you want to meet that deadline we need more resources." They would also simply not work weekends. If work didn't get done, it didn't get done.

This is obviously where imposter syndrome comes into play. If you're confident in your ability, you aren't scared you will be fired or let go for standing up for yourself.