When you say yes or no, make it a choice, not a reaction to fear. Two examples: push back on an impossible deadline with a realistic one, or decline late-night support when you need sleep. Others might get upset, but ask yourself if your answer matches who you want to be.
Chapters
Number 2 is boundaries. You say yes from choice and no from choice, not from fear. If a deadline is impossible, you say, that can't be done at that quality by Monday. But here's what I can do. If someone dumps their entire emotional world on you at 11:30, but you've got to be up for your 6:00 AM shift, you say, look, I care about this, but I also need some sleep. Let's talk tomorrow when I can actually be present. Some people won't like that. Their reaction is, "Not the scoreboard." Your question is, "Did I act according to the man I'm choosing to be?"